Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Plast Reconstr Aesthet Surg ; 72(3): 491-497, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30509737

RESUMO

Self-harm is a common source of referral to plastic and hand surgery services. Appropriate management of these patients is complex and includes the need for close liaison with mental health services. Self-harm is the single biggest risk factor for completed suicide, thereby increasing the risk by a factor of 66.1 This study aimed to analyse the clinical pathway and demographics of patients referred to plastic surgeons following self-harm. This 6-year retrospective series included patients referred to plastic surgeons following self-harm within the Galway University Hospital group. Patients were identified through the Hospital inpatient enquiry system, cross-referenced with data from the National Suicide Research Foundation. Data collected included demographics, psychiatric history, details of self-harm injury, admission pathway and operative intervention. Forty-nine patients were referred to plastic surgery services during the study period, accounting for 61 individual presentations. The male-to-female ratio was 26 (53%) to 23 (47%). Mean age was 40 years (range 21-95 years). Alcohol or illicit substance use was recorded in 17 of 61 (28%) presentations. Mortality from suicide occurred in 4 patients (8%). Mental health assessment was not carried out in 9 presentations (15%). Documentation of need for close or one-to-one observation was made in 11 cases (20%) and was not referred to in 43 cases (83%) following mental health assessment. This study demonstrates significant diversity in the management of this vulnerable patient group and may inform development of referral pathways to improve the safety of transfer, surgical admission and discharge of patients following self-harm, in consultation with mental health services.


Assuntos
Encaminhamento e Consulta , Comportamento Autodestrutivo/cirurgia , Prevenção do Suicídio , Cirurgia Plástica , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta/estatística & dados numéricos , Estudos Retrospectivos , Automutilação/psicologia , Automutilação/cirurgia , Comportamento Autodestrutivo/psicologia , Adulto Jovem
2.
World J Surg ; 43(2): 559-566, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30382292

RESUMO

BACKGROUND: Multidisciplinary team (MDT)-driven cancer care is a mandatory UK national policy, widely used globally. However, few studies have examined how MDT members make decisions as a team. We report a single-centre prospective study on team working within breast cancer MDT. METHODS: This was a prospective observational study of 10 breast MDT meetings (MDM). Trained clinical observer scored quality of presented information and disciplinary contribution to case reviews in real time, using a validated tool, namely Metric for the Observation of Decision-Making. Data were analysed to evaluate quality of team working. RESULTS: Ten MDMs were observed (N = 346 patients). An average of 42 patients were discussed per MDM (range: 29-51) with an average 3 min 20 s (range: 31 s-9 min) dedicated to each patient. Management decision was made in 99% of cases. In terms of contribution to case reviews, breast care nurses scored significantly (p < 0.05) lower (M = 1.79, SD = 0.12) compared to other team members (e.g. surgeons, M = 4.65; oncologists, M = 3.07; pathologists, M = 4.51; radiologists, M = 3.21). Information on patient psychosocial aspects (M = 1.69, SD = 0.68), comorbidities (M = 1.36, SD = 0.39) and views on treatment options (M = 1.47, SD = 0.34) was also significantly (p < 0.05) less well represented compared to radiology (M = 3.62, SD = 0.77), pathology (M = 4.42, SD = 0.49) and patient history (M = 3.91, SD = 0.48). CONCLUSION: MDT evaluation via direct observation in a meeting is feasible and reliable. We found consistent levels of quality of information coverage and contribution within the team, but certain aspects could be improved. Contribution to patient review resides predominantly with surgeons, while presented patient information is largely of biomedical nature. These findings can be fed to cancer MDTs to identify potential interventions for improvement.


Assuntos
Neoplasias da Mama/terapia , Tomada de Decisão Clínica , Equipe de Assistência ao Paciente , Feminino , Humanos , Equipe de Assistência ao Paciente/organização & administração , Estudos Prospectivos
3.
Soc Psychiatry Psychiatr Epidemiol ; 53(8): 795-801, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29704022

RESUMO

PURPOSE: Deinstitutionalisation in Ireland began following the impetus of the successful transfer of psychiatric patients into the community in other countries. This study sought to evaluate the quality of life (QoL) and social functioning (SF) of former long-stay institutionalised patients with severe and enduring mental illness who had been relocated into local community settings and followed up 10 years later. METHOD: One month prior to hospital closure, 87 former long-stay psychiatric patients, the majority of whom had a diagnosis of schizophrenia, were assessed on a range of QoL and SF measures. Patients were followed-up 10 years later in the community, to evaluate baseline predictors of quality of life and social functioning. RESULTS: Study completers (n = 35) improved significantly on a range of QoL and SF measures over the 10 year period. Specific improvements were noted in domestic skills (t = - 2.8, p < 0.0008), community skills (t = - 4.9, p < 0.001), as well as the activity and social relations measure (t = - 4.1, p < 0.001). Increased social function (t = - 6.3, p < 0.001) and improvement on the social behaviour scale (t = 7.6, p < 0.001) were noted at follow-up. Linear regression analysis found that less social behaviour problems at baseline predicted QoL 10 years later (t = - 2.6, p < 0.02). CONCLUSION: This study demonstrated that transfer into the community from an institutional environment was associated with long-term improvements in quality of life and social functioning, even in those who spent many years in the institution. Those who demonstrated the greatest improvement in QoL had less social behavioural problems at baseline assessment, providing further evidence of the success of community living for former long-stay patients.


Assuntos
Desinstitucionalização , Qualidade de Vida , Esquizofrenia/reabilitação , Psicologia do Esquizofrênico , Comportamento Social , Adulto , Feminino , Seguimentos , Hospitais Psiquiátricos , Humanos , Irlanda , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
4.
Psychol Med ; 47(9): 1609-1623, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28573962

RESUMO

BACKGROUND: Although repeatedly associated with white matter microstructural alterations, bipolar disorder (BD) has been relatively unexplored using complex network analysis. This method combines structural and diffusion magnetic resonance imaging (MRI) to model the brain as a network and evaluate its topological properties. A group of highly interconnected high-density structures, termed the 'rich-club', represents an important network for integration of brain functioning. This study aimed to assess structural and rich-club connectivity properties in BD through graph theory analyses. METHOD: We obtained structural and diffusion MRI scans from 42 euthymic patients with BD type I and 43 age- and gender-matched healthy volunteers. Weighted fractional anisotropy connections mapped between cortical and subcortical structures defined the neuroanatomical networks. Next, we examined between-group differences in features of graph properties and sub-networks. RESULTS: Patients exhibited significantly reduced clustering coefficient and global efficiency, compared with controls globally and regionally in frontal and occipital regions. Additionally, patients displayed weaker sub-network connectivity in distributed regions. Rich-club analysis revealed subtly reduced density in patients, which did not withstand multiple comparison correction. However, hub identification in most participants indicated differentially affected rich-club membership in the BD group, with two hubs absent when compared with controls, namely the superior frontal gyrus and thalamus. CONCLUSIONS: This graph theory analysis presents a thorough investigation of topological features of connectivity in euthymic BD. Abnormalities of global and local measures and network components provide further neuroanatomically specific evidence for distributed dysconnectivity as a trait feature of BD.


Assuntos
Transtorno Bipolar/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Adulto , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
J Neurocytol ; 33(1): 23-35, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15173630

RESUMO

We present an MRI-based anatomic analysis of a series of 9 human brains, representing lobar, semilobar and alobar forms of holoprosencephaly. The analysis of these variable forms of the malformation is based upon a topologic systematics established in a prior analysis of a homogeneous set of semilobar malformations. This systematics has the dual advantage that it serves both as a uniform reference for qualitative description and as a quantitative descriptive base for mathematical correlations between parameters of topology and of growth and development. Within this systematics, the prosencephalic midline is divided from caudal to rostral into diencephalic (DD-right and left, subthalamus through suprachiasmatic junction with telencephalon), telencephalic (TT-right and left, suprachiasmatic border of telencephalon midline to hippocampal commissure) and diencephalic-telencephalic (DT-right and left-hippocampal commissure through temporal limb of choroid fissure) segments. The topologic abnormality of the initial semilobar series was expressed in an orderly rostral to caudal gradient along the TT segment. In each malformation, normal midline topology began with a small posterior corpus callosum. Although the topologic anomaly in the present series invariably also involved the TT segment, this involvement was not continuous and was variably associated with anomalies of the DD in 6 and unilaterally of the DT in 1 brain. In the present as well as with the earlier series of HPE malformations but not in "normative brains," total telencephalic growth is strongly correlated with the length of the midline telencephalic segment. We propose that this system of analysis will be sensitive to the developmental stage and locus of expression of genetic and non-genetic determinants of the formal origin of HPE. For all of the present series, karyotype anlyses were normal. Mutations in the Shh and Zic2 genes were excluded in 2 cases.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/anormalidades , Holoprosencefalia/patologia , Imageamento por Ressonância Magnética/métodos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Gravidez , Resultado da Gravidez
6.
Cereb Cortex ; 13(12): 1299-312, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14615296

RESUMO

We present an MRI-based anatomic analysis of a series of seven human brains with the semilobar form of holoprosencephaly. The analysis defines a set of common descriptors for a pattern of topological anomaly which is uniform for the set of seven brains. The core of the anomaly is a rostro-caudally aligned midline gray matter 'seam' that extends from the telencephalic-suprachiasmatic junctional region to abut the posterior aspect of the callosal commissure. The seam forms the ventricular roof throughout its extent. Rostrally it is formed by the conjoined heads of caudate/accumbens nuclei. It continues caudally as a gray matter bridge in the fundus of the interhemispheric fissure, where it bridges right and left neocortex. Fornix, septal nuclei and septal limb of the choroid plexus are absent, and the telencephalic ventricles communicate with the diencephalic via open septal limbs of the choroid fissures. By contrast, the temporal limb of hippocampal formation and the choroid plexus are normal and the temporal limb of the choroid fissure is closed. This topological anomaly of conjoined left and right cortical and nuclear gray matter into a midline seam and absent septal structures is thus confined to the region of the midline telencephalic hemisphere evagination. Total telencephalic growth is strongly correlated with the length of this topologically abnormal midline telencephalic segment. The set of findings is consistent with graded failure of induction of rostral to caudal specification in the midline rostral telencephalic zone.


Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/patologia , Holoprosencefalia/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Modelos Biológicos , Envelhecimento , Criança , Pré-Escolar , Feminino , Holoprosencefalia/fisiopatologia , Humanos , Lactente , Masculino , Morfogênese , Neocórtex/crescimento & desenvolvimento , Neocórtex/patologia , Tamanho do Órgão
7.
Biol Psychiatry ; 50(12): 932-42, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11750889

RESUMO

BACKGROUND: Several recent neuroimaging studies have provided data consistent with functional abnormalities in anterior cingulate cortex in posttraumatic stress disorder (PTSD). In our study, we implemented a cognitive activation paradigm to test the functional integrity of anterior cingulate cortex in PTSD. METHODS: Eight Vietnam combat veterans with PTSD (PTSD Group) and eight Vietnam combat veterans without PTSD (non-PTSD Group) underwent functional magnetic resonance imaging (fMRI) while performing the Emotional Counting Stroop. In separate conditions, subjects counted the number of combat-related (Combat), generally negative (General Negative), and neutral (Neutral) words presented on a screen and pressed a button indicating their response. RESULTS: In the Combat versus General Negative comparison, the non-PTSD group exhibited significant fMRI blood oxygenation level-dependent signal increases in rostral anterior cingulate cortex, but the PTSD group did not. CONCLUSIONS: These findings suggest a diminished response in rostral anterior cingulate cortex in the presence of emotionally relevant stimuli in PTSD. We speculate that diminished recruitment of this region in PTSD may, in part, mediate symptoms such as distress and arousal upon exposure to reminders of trauma.


Assuntos
Emoções , Giro do Cíngulo/fisiopatologia , Imageamento por Ressonância Magnética , Córtex Pré-Frontal/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estudos de Casos e Controles , Giro do Cíngulo/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Córtex Pré-Frontal/metabolismo , Transtornos de Estresse Pós-Traumáticos/psicologia , Veteranos/psicologia , Vietnã
8.
Adv Neurol ; 85: 207-24, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11530429

RESUMO

In summary, contemporary pathophysiological models of OCD and related disorders implicate CSTC circuitry. In this chapter, we have reviewed relevant concepts related to implicit learning and more specifically, the use of an implicit sequence learning paradigm as a probe of striato-thalamic function. An initial PET investigation of patients with OCD confirmed a priori hypotheses of failure to recruit right striatum, despite the absence of a performance deficit (22). A modified version of the SRT was studied in conjunction with fMRI and yielded reliable right-lateralized striatal activation in a cohort of 10 male subjects, with clear spatial dissociation of caudate and putamen activation foci (119). Subsequent studies in our laboratory suggest that this paradigm also yields a reliable temporal window of thalamic deactivation, and hence a means for assessing thalamic gating in human subjects (120). Finally, as presented in this chapter, preliminary data from the fMRI-SRT in patients with OCD and TS as well as normal control subjects appear to replicate and extend the findings from our original PET-SRT study in OCD. Future investigations in our laboratory will seek to elaborate upon these preliminary results. In particular, we intend to study psychiatric comparison groups to establish the generalizability and/or specificity of these findings across disorders. Within OCD, we hope to explore the relationship between abnormal brain-activation patterns and symptom dimensions (34). Further, by studying subjects with remitted OCD who have been successfully treated, we hope to determine whether the observed brain-activation abnormalities represent state or trait markers. Finally, we have already begun to test a hypothesis of parallel processing deficiency in OCD by using a dual-task version of the SRT that makes simultaneous demands on implicit and explicit information processing systems (128). It is our hope that this program of research will yield new insights about OCD and related disorders, including TS. Most importantly, as other teams of investigators pursue complementary lines of inquiry, it is our wish that collective efforts in this field will lead to improved diagnosis and treatment, if not cure or prevention, for those who are afflicted with these illnesses.


Assuntos
Corpo Estriado/patologia , Transtorno Obsessivo-Compulsivo/patologia , Tálamo/patologia , Síndrome de Tourette/patologia , Corpo Estriado/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/fisiopatologia , Tálamo/fisiopatologia , Tomografia Computadorizada de Emissão , Síndrome de Tourette/diagnóstico por imagem , Síndrome de Tourette/fisiopatologia
9.
Neuroreport ; 12(2): 379-83, 2001 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-11209954

RESUMO

Repeated presentations of emotional facial expressions were used to assess habituation in the human brain using fMRI. Significant fMRI signal decrement was present in the left dorsolateral prefrontal and premotor cortex, and right amygdala. Within the left prefrontal cortex greater habituation to happy vs fearful stimuli was evident, suggesting devotion of sustained neural resources for processing of threat vs safety signals. In the amygdala, significantly greater habituation was observed on the right compared to the left. In contrast, the left amygdala was significantly more activated than the right to the contrast of fear vs happy. We speculate that the right amygdala is part of a dynamic emotional stimulus detection system, while the left is specialized for sustained stimulus evaluations.


Assuntos
Tonsila do Cerebelo/fisiologia , Expressão Facial , Medo/fisiologia , Habituação Psicofisiológica/fisiologia , Felicidade , Córtex Pré-Frontal/fisiologia , Adulto , Lateralidade Funcional/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Fatores de Tempo
10.
Emotion ; 1(1): 70-83, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12894812

RESUMO

Functional magnetic resonance imaging (fMRI) of the human brain was used to compare changes in amygdala activity associated with viewing facial expressions of fear and anger. Pictures of human faces bearing expressions of fear or anger, as well as faces with neutral expressions, were presented to 8 healthy participants. The blood oxygen-level dependent (BOLD) fMRI signal within the dorsal amygdala was significantly greater to Fear versus Anger, in a direct contrast. Significant BOLD signal changes in the ventral amygdala were observed in contrasts of Fear versus Neutral expressions and, in a more spatially circumscribed region, to Anger versus Neutral expressions. Thus, activity in the amygdala is greater to fearful facial expressions when contrasted with either neutral or angry faces. Furthermore, directly contrasting fear with angry faces highlighted involvement of the dorsal amygdaloid region.


Assuntos
Tonsila do Cerebelo/anatomia & histologia , Tonsila do Cerebelo/irrigação sanguínea , Ira , Expressão Facial , Medo , Imageamento por Ressonância Magnética , Adulto , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Oxigênio/sangue
11.
Neuroreport ; 11(11): 2351-5, 2000 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-10943684

RESUMO

Here we describe response in the human amygdala to the presentation of racial outgroup vs ingroup faces. Functional magnetic resonance imaging (fMRI) measures of brain activity were acquired while subjects who identified themselves as White or Black viewed photographs of both White and Black faces. Across all subjects, we observed significantly greater blood oxygen-level-dependent (BOLD) signal in the amygdala to outgroup vs ingroup faces, but only during later stimulus presentations. A region of interest (ROI)-based analysis of these voxels revealed a significant interaction between amygdala response to outgroup and ingroup faces over time. Specifically, the greater amygdala activation to outgroup faces during later stimulus presentations was the result of amygdala response habituation to repeated presentations of ingroup faces with sustained responses to outgroup faces. The present results suggest that amygdala responses to human face stimuli are affected by the relationship between the perceived race of the stimulus face and that of the subject. Results are discussed as consistent with a role for the amygdala in encoding socially and/or biologically relevant information. We conclude that researchers seeking to study brain responses to face stimuli in human subjects should consider the relationship between the race of subjects and stimuli as a significant potential source of variance. Moreover, these data provide a foundation for future related studies in the neuroscience of social cognition and race.


Assuntos
Tonsila do Cerebelo/fisiologia , Emoções/fisiologia , Vias Neurais/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Relações Raciais/psicologia , Adulto , Tonsila do Cerebelo/anatomia & histologia , População Negra , Mapeamento Encefálico , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/anatomia & histologia , Testes Neuropsicológicos , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , População Branca
12.
Biol Psychiatry ; 47(9): 769-76, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10812035

RESUMO

BACKGROUND: Converging lines of evidence have implicated the amygdala in the pathophysiology of posttraumatic stress disorder (PTSD). We previously developed a method for measuring automatic amygdala responses to general threat-related stimuli; in conjunction with functional magnetic resonance imaging, we used a passive viewing task involving masked presentations of human facial stimuli. METHODS: We applied this method to study veterans with PTSD and a comparison cohort of combat-exposed veterans without PTSD. RESULTS: The findings indicate that patients with PTSD exhibit exaggerated amygdala responses to masked-fearful versus masked-happy faces. CONCLUSIONS: Although some previous neuroimaging studies of PTSD have demonstrated amygdala recruitment in response to reminders of traumatic events, this represents the first evidence for exaggerated amygdala responses to general negative stimuli in PTSD. Furthermore, by using a probe that emphasizes automaticity, we provide initial evidence of amygdala hyperresponsivity dissociated from the "top-down" influences of medial frontal cortex.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Córtex Cerebral/fisiopatologia , Face , Lobo Frontal/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
13.
Psychopharmacology (Berl) ; 147(2): 190-9, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10591887

RESUMO

RATIONALE: Psychomotor stimulant drugs engender intense euphoria as well as anxiogenic effects, both potentially involving the mesolimbic dopamine system. OBJECTIVES: (1) Do animals that discriminate a psychomotor stimulant drug from saline generalize to a non-pharmacological stressful event such as social defeat? (2) How does the generalization from d-amphetamine to social defeat stress relate to dopamine overflow in the mesocorticolimbic system in response to this stress? METHODS: Adult male Long-Evans rats were trained to discriminate either 1.0 mg/kg d-amphetamine or 10 mg/kg cocaine from saline in a two-lever drug discrimination task; each injection-appropriate tenth lever press was reinforced by milk presentation (fixed ratio, FR10). After confirming systematic cocaine and d-amphetamine dose-effect curves, additional discrimination tests involved exposure to several stress conditions; (1) brief confrontations with an aggressive resident rat that resulted in the intruder's defeat. Rats were administered saline, then exposed to aggressive threats behind a protective screen for 15 min, and subsequently performed the two-lever discrimination task; (2) exposure for 15 min to aggressive threats without prior defeat; (3) exposure to a novel cage for 15 min. A subgroup of rats was prepared for in vivo microdialysis after they generalized the social stress response to the d-amphetamine cue. RESULTS: Nine of 35 d-amphetamine-trained and six of 18 cocaine-trained animals responded at least 80% at the drug-appropriate lever after social defeat stress. Social defeat stress increased dopamine in nucleus accumbens, with a closely similar dopamine response in amphetamine-discriminating rats that were behaviorally sensitized versus those that were not sensitized by amphetamine. CONCLUSIONS: Generalization from social stress to the stimulant "cue" differs among individuals, which may be relevant to the anxiety-like effects of stimulants. By contrast, mesolimbic DA activity and motor activity was increased in response to social defeat stress or a d-amphetamine challenge, regardless of the qualitatively different stimulant-stress generalization. Mesolimbic DA in response to stress or amphetamine appears significant in behavioral activation, but not in the qualitatively divergent internal stimulus properties.


Assuntos
Anfetamina/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Cocaína/farmacologia , Discriminação Psicológica/efeitos dos fármacos , Dopamina/metabolismo , Estresse Fisiológico/metabolismo , Animais , Sinais (Psicologia) , Dominação-Subordinação , Relação Dose-Resposta a Droga , Masculino , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Ratos , Ratos Long-Evans
14.
Biol Psychiatry ; 44(12): 1219-28, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9861465

RESUMO

BACKGROUND: The emotional counting Stroop (ecStroop) functional magnetic resonance imaging (fMRI) activation paradigm was designed to recruit the anterior cingulate affective division (ACad). METHODS: Nine normal, healthy male and female subjects (mean age 24.2 years) reported via button press the number of neutral and negative words that appeared on a screen while reaction time and fMRI data were acquired. RESULTS: We observed a) greater ACad activation for negative versus neutral words during initial presentation blocks; b) lower overall ACad signal intensity during task performance (i.e., both negative and neutral words) compared to the baseline fixation condition; and c) no reaction time increase to negative versus neutral words. CONCLUSIONS: In a companion study of a cognitive version of the counting Stroop (Bush et al 1998), these same 9 subjects a) activated the more dorsal anterior cingulate cognitive division; b) also showed the overall decrease in ACad signal intensity; and c) demonstrated a reliable reaction time effect. Taken together, these data offer a within-group spatial dissociation of AC function based upon information content (i.e., cognitive vs. emotional) and/or presence of behavioral interference. We propose that the ecStroop will be a useful fMRI probe of ACad function in anxiety disorders.


Assuntos
Emoções/fisiologia , Giro do Cíngulo/fisiologia , Adulto , Mapeamento Encefálico , Cognição/fisiologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Testes Psicológicos , Tempo de Reação , Valores de Referência
15.
Hum Brain Mapp ; 6(4): 270-82, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9704265

RESUMO

The anterior cingulate cortex has been activated by color Stroop tasks, supporting the hypothesis that it is recruited to mediate response selection or allocate attentional resources when confronted with competing information-processing streams. The current study used the newly developed "Counting Stroop" to identify the mediating neural substrate of cognitive interference. The Counting Stroop, a Stroop variant allowing on-line response time measurements while obviating speech, was created because speaking produces head movements that can exceed those tolerated by functional magnetic resonance imaging (fMRI), preventing the collection of vital performance data. During this task, subjects report by button-press the number of words (1-4) on the screen, regardless of word meaning. Interference trials contain number words that are incongruent with the correct response (e.g., "two" written three times), while neutral trials contain single semantic category common animals (e.g., "bird"). Nine normal right-handed adult volunteers underwent fMRI while performing the Counting Stroop. Group fMRI data revealed significant (P < or = 10(-4) activity in the cognitive division of anterior cingulate cortex when contrasting the interference vs. neutral conditions. On-line performance data showed 1) longer reaction times for interference blocks than for neutral ones, and 2) decreasing reaction times with practice during interference trials (diminished interference effects), indicating that learning occurred. The performance data proved to be a useful guide in analyzing the image data. The relative difference in anterior cingulate activity between the interference and neutral conditions decreased as subjects learned the task. These findings have ramifications for attentional, cognitive interference, learning, and motor control mechanism theories.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Cognição/fisiologia , Percepção de Cores , Giro do Cíngulo/fisiologia , Tempo de Reação/fisiologia , Adulto , Feminino , Humanos , Idioma , Imageamento por Ressonância Magnética/métodos , Masculino , Córtex Motor/fisiologia , Sistemas On-Line , Lobo Parietal/fisiologia , Reprodutibilidade dos Testes , Semântica
16.
Neuroreport ; 9(5): 865-70, 1998 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-9579681

RESUMO

Previous research has implicated the striatum in implicit sequence learning. However, imaging findings have been inconsistent with regard to activity within the thalamus during performance of such tasks. Contemporary models of cortico-striato-thalamic circuitry suggest opposing influences on thalamic activity; suppression of thalamic activity is mediated by the indirect pathway and enhancement is mediated by the direct pathway. Using functional magnetic resonance imaging, we studied activity within human thalamus during early and late phases of an implicit sequence learning task known to reliably recruit the striatum. Significant deactivation (decreased signal relative to a baseline condition) was observed within the thalamus during early implicit learning. This finding is consistent with models of cortico-striato-thalamic function and specifically supports a profile of early 'thalamic gating' via the indirect pathway.


Assuntos
Aprendizagem/fisiologia , Tálamo/fisiologia , Gânglios da Base/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Neostriado/fisiologia , Vias Neurais/fisiologia , Tempo de Reação/fisiologia
17.
J Neurosci ; 18(1): 411-8, 1998 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9412517

RESUMO

Functional magnetic resonance imaging (fMRI) of the human brain was used to study whether the amygdala is activated in response to emotional stimuli, even in the absence of explicit knowledge that such stimuli were presented. Pictures of human faces bearing fearful or happy expressions were presented to 10 normal, healthy subjects by using a backward masking procedure that resulted in 8 of 10 subjects reporting that they had not seen these facial expressions. The backward masking procedure consisted of 33 msec presentations of fearful or happy facial expressions, their offset coincident with the onset of 167 msec presentations of neutral facial expressions. Although subjects reported seeing only neutral faces, blood oxygen level-dependent (BOLD) fMRI signal in the amygdala was significantly higher during viewing of masked fearful faces than during the viewing of masked happy faces. This difference was composed of significant signal increases in the amygdala to masked fearful faces as well as significant signal decreases to masked happy faces, consistent with the notion that the level of amygdala activation is affected differentially by the emotional valence of external stimuli. In addition, these facial expressions activated the sublenticular substantia innominata (SI), where signal increases were observed to both fearful and happy faces--suggesting a spatial dissociation of territories that respond to emotional valence versus salience or arousal value. This study, using fMRI in conjunction with masked stimulus presentations, represents an initial step toward determining the role of the amygdala in nonconscious processing.


Assuntos
Tonsila do Cerebelo/fisiologia , Conscientização/fisiologia , Expressão Facial , Medo/fisiologia , Felicidade , Adulto , Lateralidade Funcional/fisiologia , Frequência Cardíaca , Humanos , Imageamento por Ressonância Magnética , Masculino , Substância Inominada/fisiologia
18.
J Pharmacol Exp Ther ; 282(2): 1020-7, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9262371

RESUMO

The dopamine D4 selective ligand, [H]NGD 94-1, was used in these studies to characterize binding sites in rat and human brain tissue by membrane binding and autoradiography techniques. Autoradiographic analysis of rat brain showed that specific [3H]NGD 94-1 binding was greatest in entorhinal cortex, lateral septal nucleus, hippocampus and the medial preoptic area of the hypothalamus. This nonstriatal distribution of [3H]NGD 94-1 binding was distinct from the autoradiographic distribution of dopamine D2 and D3 receptor subtypes. In homogenate preparations from rat brain regions, [3H]NGD 94-1 binding sites were low in density (<30.0 fmol/mg protein). The low density of D4 binding sites was corroborated by autoradiographic comparisons in which binding density for D4 receptors as measured by [3H]NGD 94-1 was only 1/7 of D2 and 1/5 of D3 receptor densities, despite corrections for differing radioligand binding characteristics. Pharmacological evaluation showed high affinity at rat [3H]NGD 94-1 binding sites for compounds with known D4 receptor affinity and little displacement by compounds with affinity for dopamine D1/D2/D3 receptor subtypes. Specific, high-affinity [3H]NGD 94-1 binding was also present in several human brain regions, including hippocampus, hypothalamus, dorsal medial thalamus, entorhinal cortex, prefrontal cortex and lateral septal nucleus. High-affinity [3H]NGD 94-1 binding was not present in any human striatal region examined. The pharmacological profile of [3H]NGD 94-1 binding sites in human brain was consistent with that previously demonstrated for cloned human D4 receptors expressed in mammalian cells. These findings suggest that specific, high-affinity [3H]NGD 94-1 binding exists in rat and human brain and that these sites reflect populations of dopamine D4 receptors with a distribution unique among dopamine receptor subtypes.


Assuntos
Encéfalo/metabolismo , Antagonistas de Dopamina/metabolismo , Imidazóis/metabolismo , Pirimidinas/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Autorradiografia , Antagonistas dos Receptores de Dopamina D2 , Humanos , Masculino , Racloprida , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D4 , Salicilamidas/metabolismo , Tetra-Hidronaftalenos/metabolismo , Trítio
19.
J Endod ; 18(8): 376-8, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1431692

RESUMO

Thirty-six maxillary central incisors were prepared in a manner similar to nonvital bleaching procedures. They were examined with respect to the degree of procion green dye penetration of dentin with and without heating. Cavit, IRM, and zinc phosphate cement were used to evaluate their sealing ability. Cavit and IRM provided better internal sealing of the dentin than did zinc phosphate cement.


Assuntos
Sulfato de Cálcio , Cimentos Dentários , Metilmetacrilatos , Polivinil , Materiais Restauradores do Canal Radicular , Cimento de Óxido de Zinco e Eugenol , Óxido de Zinco , Cimento de Fosfato de Zinco , Infiltração Dentária/prevenção & controle , Permeabilidade da Dentina , Combinação de Medicamentos , Humanos , Incisivo , Teste de Materiais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...