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1.
Occup Med (Lond) ; 70(6): 421-426, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32740664

RESUMO

BACKGROUND: While the potential buffering effects of spirituality are well established in the general population, how spirituality affects those in extremely high-stress occupations like the military and law enforcement is less clear. AIMS: This paper explores the possibility that spiritual influences may operate differently among military veterans than other people. It specifically proposes that attendance at religious services is an especially important buffer for combat veterans. METHODS: This study engaged in a secondary analysis of 74 480 respondents from the National Survey on Drug Use and Health for the years 2013-17. The respondents were split into four groups; veterans with combat experience before September 2001, veterans with combat experience since September 2001, veterans with no combat experience and non-veterans. RESULTS: The likelihood of mental illness decreased in the general population along three different measures of religion; the importance of religion, friendships that shared religious beliefs and attendance at religious services. The relationship was weak and disappeared when controls for non-religion variables were included. A major exception was combat veterans, for whom the religious effects were limited to attendance at services, and the effect survived with the addition of non-religion control variables. CONCLUSIONS: Mental health professionals, chaplains, pastoral counsellors and clergy need to recognize that among the therapeutic benefits of religious attendance and recognize the value of the religious rituals as ends in themselves.


Assuntos
Transtornos Mentais/epidemiologia , Religião , Veteranos/psicologia , Adulto , Conflitos Armados/estatística & dados numéricos , Amigos/psicologia , Humanos , Masculino , Inquéritos e Questionários , Estados Unidos/epidemiologia
2.
Am J Transplant ; 14(5): 1136-41, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24698537

RESUMO

Chronic inflammation may contribute to human immunodeficiency virus (HIV) persistence through a number of potential pathways. We explored the impact of immunosuppressant therapy on peripheral blood measures of HIV persistence following kidney transplantation. Stored plasma and peripheral blood mononuclear cells prior to transplantation and at weeks 12, 26, 52 and 104 posttransplant were obtained from 91 transplant recipients. In a multivariate model, higher pretransplant plasma HIV RNA level (p < 0.0001) and a longer duration of follow-up posttransplant (p = 0.09) were associated with higher posttransplant plasma HIV RNA levels. A higher baseline HIV DNA (p < 0.0001) was significantly associated with higher HIV DNA levels posttransplant, while higher CD4+ T cell count (p = 0.001), sirolimus use (p = 0.04) and a longer duration of follow-up (p = 0.06) were associated with lower posttransplant HIV DNA levels. The association between sirolimus exposure and lower frequency of cells containing HIV DNA levels posttransplant suggest that the immune-modifying drugs may affect the level of HIV persistence during effect therapy. Future studies of sirolimus as a reservoir-modifying agent are warranted.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Infecções por HIV/prevenção & controle , Imunossupressores/uso terapêutico , Falência Renal Crônica/cirurgia , Transplante de Rim , Feminino , Seguimentos , HIV/genética , HIV/isolamento & purificação , HIV/metabolismo , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/virologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Viral/sangue , Estudos Retrospectivos , Taxa de Sobrevida , Transplantados
3.
J Appl Toxicol ; 21(3): 199-209, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11404831

RESUMO

In an effort to assess potential ecological hazards to amphibian species in selected regions within New Hampshire, the traditional Frog Embryo Teratogenesis Assay-Xenopus (FETAX), a 14-/21 day tail resorption thyroid disruption assay and >30 day limb development tests were conducted with representative surface water and sediment samples. Two separate sets of samples collected from five sites were evaluated. The primary objectives of the study were to determine if samples were capable of inducing early embryo-larval maldevelopment, to determine if maldevelopment included limb defects, to determine if thyroxine co-administration altered the rates of limb malformation and to evaluate the impact of the samples on growth rates, developmental progress and metamorphic climax. Results from these studies suggested that pond water and sediment extract samples, but not whole sediment samples, from B2, FW, LP and W ponds were capable of inducing abnormal early embryo-larval development. In addition, water samples from B2 and W ponds induced significant abnormal hindlimb development. Some abnormal forelimb development was noted in the tail resorption studies, but not to the same extent as the hindlimbs. Each of the water samples induced appreciable developmental delay, including the paired reference site B1, which could be reversed by the addition of exogenous thyroxine.


Assuntos
Desenvolvimento Embrionário , Metamorfose Biológica/efeitos dos fármacos , Teratogênicos/toxicidade , Poluentes da Água/efeitos adversos , Xenopus/crescimento & desenvolvimento , Animais , Membro Anterior/anormalidades , Sedimentos Geológicos , Membro Posterior/anormalidades , Larva/crescimento & desenvolvimento , Xenopus/embriologia
4.
Drug Chem Toxicol ; 24(2): 103-15, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11360429

RESUMO

The developmental toxicity of cyclophosphamide, coumarin, 2-acetyl-aminofluorine (2-AAF), and trichloroethylene (TCE) was assessed with Frog Embryo Teratogenesis Assay: Xenopus (FETAX). Late Xenopus laevis blastulae were exposed to each test material for 96-h in two separate static-renewal tests with and without the presence of five differently induced exogenous metabolic activation systems (MAS). The MAS consisted of Aroclor 1254- (Aroclor 1254 MAS), isoniazid- (INH MAS), phenobarbital- (PB MAS), or beta-naphthoflavone- (beta-NF MAS), or a post-isolation mixture (mixed MAS) of INH-, PB-, and beta-NF-induced rat liver microsomes. Addition of the Aroclor 1254 MAS bioactivated cyclophosphamide, coumarin, 2-AAF, but not TCE. Addition of the PB MAS bioactivated cyclophosphamide, weakly bioactivated coumarin and 2-AAF, but had no effect on TCE developmental toxicity. The beta-NF MAS bioactivated coumarin and 2-AAF, weakly bioactivated cyclophosphamide, but did not alter the developmental toxicity of TCE. Addition of the INH-induced MAS only bioactivated TCE, whereas the post-isolation mixed MAS bioactivated each test material. Based on LC50 and EC50 (malformation) values, embryo growth, and types and severity of induced malformations, each test material was developmentally toxic. Use of post-microsome isolation mixtures from differentially induced rat livers increased the efficacy of the exogenous MAS routinely used by FETAX.


Assuntos
Biotransformação , Embrião de Mamíferos/efeitos dos fármacos , Embrião não Mamífero , Testes de Toxicidade , Xenopus laevis/embriologia , 2-Acetilaminofluoreno/toxicidade , Anormalidades Induzidas por Medicamentos/etiologia , Animais , Cumarínicos/toxicidade , Ciclofosfamida/toxicidade , Isoniazida , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Fenobarbital , Ratos , Tricloroetileno/toxicidade , beta-Naftoflavona
5.
Drug Chem Toxicol ; 24(2): 117-27, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11360430

RESUMO

The developmental toxicities of five test compounds including carbon tetrachloride, urethane, phenacetin, parathion, and chloroform, were evaluated using Frog Embryo Teratogenesis Assay--Xenopus (FETAX), with minor modification. Post-isolation mixtures of differently-induced rat liver microsomes (phenobarbital- (PB), beta-naphthoflavone- (beta-NF), and isoniazid- (INH)-induced preparations) were co-cultured directly with X. laevis embryos. Results from these studies suggest that the Aroclor 1254-induced MAS could effectively be replaced by a mixed lot of PB-, beta-NF-, and INH-induced rat liver microsomes. Each of the test materials were found to be developmentally toxic when bioactivated by the mixed MAS.


Assuntos
Biotransformação , Embrião de Mamíferos/efeitos dos fármacos , Embrião não Mamífero , Testes de Toxicidade , Xenopus laevis/embriologia , Anormalidades Induzidas por Medicamentos/etiologia , Animais , Tetracloreto de Carbono/toxicidade , Clorofórmio/toxicidade , Técnicas de Cocultura , Isoniazida , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Paration/toxicidade , Fenacetina/toxicidade , Fenobarbital , Ratos , Uretana/toxicidade , beta-Naftoflavona
6.
Biol Trace Elem Res ; 77(2): 173-87, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11101049

RESUMO

Sets of adult male and female Xenopus laevis were administered a boron-deficient (-B) diet under low-boron culture conditions, a boron-supplemented (+B) diet under ambient boron culture conditions, a copper-deficient (-Cu) diet under low-copper culture conditions, or a copper-supplemented (+Cu) diet under ambient copper culture conditions, for 120 d. Adults from each group were' subsequently bred, and the progeny were cultured and bred. Results from these studies indicated that although pronounced effects on adult reproduction and early embryo-larval development were noted in the -B F1 generation, no effects on limb development were observed. No significant effects on reproduction, early embryogenesis, or limb development were noted in the +B group, irrespective of generation. Highly specific forelimb and hindlimb defects, including axial flexures resulting in crossed limbs and reduction deficits, were observed in -B F2 larvae, but not in the +B F2 larvae. As was noted in the boron-deficiency studies, significant effects on reproduction and early embryo development were observed in the -Cu F1 generation, but not in the +Cu F, generation. Unlike the effects associated with boron deficiency, maldevelopment of the hindlimbs (32 responders, n = 40) was found in the F1 generation.


Assuntos
Boro/deficiência , Cobre/deficiência , Deformidades Congênitas dos Membros/etiologia , Xenopus laevis/embriologia , Animais , Feminino , Masculino
7.
J Appl Toxicol ; 20(5): 419-25, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11139173

RESUMO

Short-term static-renewal studies were performed on Xenopus laevis embryos with 16 selected test materials from day 50 (stage 60) to day 64 (stage 66) (14-day test) to evaluate effects on tail resorption and thyroid function. Of the 16 test materials, nine were found to inhibit significantly the rate of tail resorption, four were found to stimulate metamorphosis and three had no appreciable effect on the rate of metamorphosis. In an effort to determine if the morphological effects observed were related to alteration in thyroid activity, measurement of triiodothyronine (T3) in the test organisms and coadministration studies using thyroxine (agonist) or propylthiouracil (antagonist) were performed based on the morphological response noted during tail resorption. Of the nine compounds found to inhibit the rate of tail resorption, six were found to reduce the levels of T3. In each case, the inhibitory response could be at least partially alleviated by the co-administration of thyroxine. Larvae exposed to the four stimulatory agents had somewhat elevated levels of T3 and were responsive to propylthiouracil antagonism. These results suggest that 12 of the 14 compounds tested in this study that altered the rate of tail resorption did so via the thyroid axis. Overall, the X. laevis model appeared to be a suitable system for evaluating the impact of environmental agents and chemical products on thyroid function.


Assuntos
Metamorfose Biológica/efeitos dos fármacos , Glândula Tireoide/fisiologia , Animais , Antitireóideos/farmacologia , Larva , Modelos Biológicos , Propiltiouracila/farmacologia , Cauda/crescimento & desenvolvimento , Testes de Função Tireóidea , Tiroxina/farmacologia , Tri-Iodotironina/sangue , Xenopus laevis
9.
Am J Hematol ; 57(4): 326-30, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9544978

RESUMO

A patient with multiple myeloma was noted to have an IgA deficiency during investigation of a possible transfusion reaction due to IgA deficiency and anti-IgA. Because of the patient's age, otherwise good health, and early stage of disease, he was enrolled in a research treatment protocol that involved an allogeneic bone marrow transplant (BMT). The BMT successfully put the patient in complete remission from his multiple myeloma and corrected his IgA deficiency. Class-specific IgG anti-IgA antibody that had been identified prior to BMT was no longer detectable in his plasma. Anaphylactic transfusion reactions were successfully avoided by using a combination of IgA-deficient and washed blood components including the marrow graft, and IgA-reduced intravenous immunoglobulin.


Assuntos
Transplante de Medula Óssea/imunologia , Deficiência de IgA/terapia , Mieloma Múltiplo/terapia , Adulto , Anticorpos Anti-Idiotípicos/metabolismo , Transfusão de Sangue , Humanos , Imunoglobulina A/imunologia , Masculino
10.
Addict Behav ; 23(1): 1-6, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9468735

RESUMO

Social physique anxiety (SPA) is highly correlated with other body image measures that have been considered to be important in understanding eating disorders. However, SPA has not been directly studied with respect to eating disorders. Thus, the purpose of this investigation was to examine the link between SPA and measures of eating disorder symptomatology to determine if SPA should be considered as an additional risk factor in the prediction of eating disturbances. One hundred and sixty female undergraduates completed questionnaires measuring body mass index (BMI), social physique anxiety (SPAS), anorexic symptoms (EAT), bulimic symptoms (BULIT-R), depression (CES-D), self-esteem (SES) and obligatory exercise (OEQ). Regression analyses revealed that SPA and depression were the psychological correlates that predicted bulimic symptomatology and that SPA, depression, and obligatory exercise predicted anorexic symptomatology; all variables were positively related to eating disorder symptoms. Overall, the results indicate that social physique anxiety appears to be a useful construct for understanding eating disorder symptoms in female undergraduates.


Assuntos
Anorexia/psicologia , Ansiedade/psicologia , Imagem Corporal , Bulimia/psicologia , Ajustamento Social , Adulto , Depressão/psicologia , Exercício Físico/psicologia , Feminino , Humanos , Análise de Regressão , Fatores de Risco , Autoimagem
11.
Exp Neurol ; 146(2): 536-45, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9270065

RESUMO

The effect of varying the volume of grafted fetal mesencephalic tissue was studied in patients with idiopathic Parkinson's disease in a single-blinded study. Evaluations were performed according to the Core Assessment Program for Intracerebral Transplantation and videotaped both prior to transplantation and in 3-month intervals after transplantation. One group, low-volume grafts (six subjects; mean age, 57.2 years), received ventral mesencephalon grafts from one to two donors with an approximate volume up to 20 mm3, while the second group, high-volume grafts (seven subjects; mean age, 59.5 years), received ventral mesencephalon grafts from three or more donors with an approximate volume of 24 mm3. Both groups of patients demonstrated significant improvement over presurgical baseline scores on all major parameters. The high-volume group had significantly greater improvements on all the UPDRS scores and also better performance on a variety of motor performance tasks over that seen among low-volume patients. These results indicate that variations of fetal graft volume do have an impact on clinical outcome.


Assuntos
Corpo Estriado/cirurgia , Transplante de Tecido Fetal/métodos , Mesencéfalo/embriologia , Doença de Parkinson/cirurgia , Idoso , Relação Dose-Resposta a Droga , Feminino , Humanos , Levodopa/administração & dosagem , Levodopa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/fisiopatologia , Índice de Gravidade de Doença , Resultado do Tratamento
12.
Int J Psychophysiol ; 25(2): 123-37, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9101337

RESUMO

This study used magnetoencephalography to examine the possibility that different generators account for the long-latency event-related potential (P300), evoked by rare target and by rare non-target, novel visual stimuli, in a visual oddball counting task performed by seven subjects. As expected, P300 peak latency was longer in response to rare targets compared to novel, non-target stimuli. Two main source regions were found for the Target- as well as for the Novel-P300, one in the temporal and one in the occipital lobe. Centers of neural activity were observed in the vicinity of the superior temporal sulcus, in the hippocampal formation and parahippocampal gyrus and in the occipital extrastriate cortex. It appears that the brain structures which contributed to the generation of the P300 response to both the target and the novel visual stimuli overlapped to a great extent.


Assuntos
Encéfalo/fisiologia , Potenciais Evocados P300/fisiologia , Magnetoencefalografia , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa
13.
Cell Transplant ; 5(2): 327-37, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8689043

RESUMO

This study reports our findings from 22 patients (ages ranging from 42 to 73 yr; mean = 55.2) with recalcitrant idiopathic Parkinson's disease (PD) who received implants of fetal ventral mesencephalic tissue using an MRI-guided stereotactic procedure and who have been followed for at least 6 mo postoperatively, employing the guidelines established by the Core Assessment Program for Intracerebral Transplantations. Evaluations were videotaped and were performed both on and off levodopa medications. To date, we have seven patients with 24 mo, three with 18 mo, three with 12 mo, and nine with 6 mo post-surgical assessments. Comparing surgical outcomes to levels prior to fetal transplants we found: 1) mean levodopa levels were reduced 46% at 6 mo, 12% at 12 mo, 20% at 18 mo, and 54% at 24 mo; 2) Unified Parkinson's Disease Rating Scale (UPDRS) scores with patients on levodopa were improved by an average of 38% (6 mo), 50.2% (12 mo), 69.3% (18 mo), and 73.9% (24 mo), while off medication scores showed reductions ranging from 24.7% at 6 mo to 55.1% at 24 mo. Other measures, including Hoehn-Yahr staging, Activities of Daily Living, and dyskinesia rating scales, were also significantly improved following fetal transplants. Timed motor tasks (finger dexterity, supination-pronation, foot tapping, and Stand-Walk-Sit) performance also demonstrated highly significant improvements. Patient's self-rating scores indicated that the patients typically perceived substantial improvements in their condition. However, substantial variability in the improvements following surgery still persists and range from nominal improvements in performance to significant changes that can be classified as altering the overall lifestyle of the patients. To date, 4 of the 22 subjects were considered by the physicians to be nonresponders; that is, there were no clinically relevant improvements in these patients' conditions.


Assuntos
Transplante de Tecido Encefálico , Transplante de Tecido Fetal , Mesencéfalo/transplante , Doença de Parkinson/cirurgia , Atividades Cotidianas , Idoso , Interpretação Estatística de Dados , Feminino , Humanos , Levodopa/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/diagnóstico , Transtornos dos Movimentos/tratamento farmacológico , Transtornos dos Movimentos/cirurgia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/psicologia , Satisfação do Paciente , Resultado do Tratamento
14.
J Neurosci Methods ; 64(2): 163-72, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8699877

RESUMO

We present a new procedure for localizing simultaneously active multiple brain sources that overlap in both space and time on EEG recordings. The source localization technique was based on a spatio-temporal model and a genetic algorithm search routine. The method was successfully applied to the localization of two dipole sources from several sets of simulated potentials with various signal-to-noise ratios (SNR). The different SNR values resembled evoked responses and epileptic spikes as commonly seen in the laboratory. Results of the simulation studies yielded localization accuracy ranging from 0.01 to 0.07 cm with an SNR of 10; from 0.02 to 0.26 cm with an SNR of 5; and from 0.06 to 0.73 cm when the SNR was equal to 2. Additionally, two sets of simulations were based on the dipole arrangements and time activities of data obtained during electrical stimulation of the median nerve in human subjects. These studies yielded localization accuracy within 0.1 cm. We also studied the localization accuracy of the algorithm using a physical model incorporating potential measurements of two current dipoles embedded in a sphere. In this situation the algorithm was successful in localizing the two simultaneously active sources to within 0.07-0.15 cm.


Assuntos
Algoritmos , Simulação por Computador , Eletroencefalografia , Modelos Genéticos , Encéfalo/fisiologia , Estimulação Elétrica , Eletrodos Implantados , Campos Eletromagnéticos , Potenciais Evocados/fisiologia , Humanos , Reprodutibilidade dos Testes
15.
Electroencephalogr Clin Neurophysiol ; 94(2): 109-14, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7532571

RESUMO

We tested the localization accuracy of magnetoencephalography (MEG) and electrocorticography (ECoG) for a current dipole in a saline filled sphere at depths ranging from 1 to 6 cm at 1 cm intervals. We used standard neuromagnetometer placements and subdural electrode grids, previously employed for patient studies, with precise measurements of sensor and electrode locations with a 3-dimensional spatial digitizer. MEG and ECoG had comparable accuracy with mean errors of 1.5 and 1.8 mm, respectively. It appears that use of the spatial digitizer increases accuracy for both MEG and EGoG localizations. The larger errors in the ECoG with increasing depths could be attributed to under-sampling of the spatial pattern of the field which spreads out with deeper sources. It should be noted that in clinical applications a grid of the dimensions used here would most typically be used for superficial sources on the cortex with depth recordings being preferred for investigations of deep epileptogenic activity. Results are encouraging for continued development of non-invasive MEG methods for further definition of epileptogenic zones in the brain.


Assuntos
Córtex Cerebral/fisiologia , Magnetoencefalografia , Modelos Neurológicos , Córtex Cerebral/fisiopatologia , Eletroencefalografia , Humanos , Matemática , Modelos Teóricos , Reprodutibilidade dos Testes
16.
J Clin Apher ; 10(4): 194-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8770712

RESUMO

Our practice is to defer donors with blood platelet (PLT) counts of < 180 x 10(9)/L because PLT yields are low, when compared to PLT units collected from donors with higher counts. In an attempt to minimize deferral, we determined whether 33 donors, who repeatedly demonstrated low-normal PLT counts (150-180 x 10(9)/L) on multiple occasions during the prestudy period. might safely donate satisfactory apheresis PLT units simply by extending the apheresis collection time by 20 min (men) and 40 min (women). Repeat plateletpheresis procedures were scheduled at > or = 28-day intervals. The mean PLT yield (N = 92) was 5.8 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. Although donors entered the study only after they had repeatedly exhibited predonation PLT counts of < 180 x 10(9)/L, PLT counts were not always below this level at the time of study collections. However, analyzing only donations with true predonation PLT counts of < 180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. The average fall in donor blood PLT counts (pre-vs. postdonation) was 36%, with only ten of 99 postdonation counts being < 100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis collection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units.


Assuntos
Doadores de Sangue , Plaquetoferese/efeitos adversos , Feminino , Humanos , Masculino , Contagem de Plaquetas , Resultado do Tratamento
17.
Electroencephalogr Clin Neurophysiol ; 91(3): 171-8, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7522146

RESUMO

In order to delineate the characteristics of epileptic spikes, 1946 different spikes were studied in 6 patients with complex partial epilepsy. Non-invasive MEG and EEG source analysis of interictal spikes were contrasted to ECoG localization, surgical outcome and presence of lesions on MRI. Results indicated that: (1) using the most frequent occurring spike topography patterns from a large sample of spikes improved goodness-of-fit values for both MEG and EEG localization, (2) when spike patterns could be appropriately matched on several successive MEG measurements to provide an adequate matrix (3 of 6 subjects), there was excellent agreement between MEG dipole sources and ECoG sources as well as surgical outcome and presence of MRI lesions, (3) EEG source analyses also gave good results but not as consistently as MEG.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiopatologia , Epilepsias Parciais/fisiopatologia , Adulto , Córtex Cerebral/fisiopatologia , Estimulação Elétrica , Eletroencefalografia , Eletroculografia , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Humanos , Magnetoencefalografia , Masculino
18.
Neurology ; 44(7): 1283-6, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8035931

RESUMO

We studied evoked magnetic fields and electrical potentials following stimulation of the tibial nerve in a group of 24 normal subjects. Both magnetic and electrical recordings demonstrated a series of oscillatory patterns consisting of four peaks (two positive and two negative) occurring between 40 and 100 msec. Magnetic field source localization of all four peaks using a dipole-in-a-sphere model indicated that all four peaks emanated from the same cortical surface located within the longitudinal fissure, an area typically associated with somatosensory function.


Assuntos
Potenciais Somatossensoriais Evocados , Nervo Tibial/fisiologia , Adulto , Encéfalo/anatomia & histologia , Estimulação Elétrica , Feminino , Humanos , Imageamento por Ressonância Magnética , Magnetismo , Masculino , Pessoa de Meia-Idade , Oscilometria
19.
Electroencephalogr Clin Neurophysiol ; 90(2): 157-65, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7510630

RESUMO

Slow magnetic fields concurrent with two successive contingent negative variations (CNVs) were elicited in 8 subjects during visual recognition tasks involving pattern versus place discrimination. All stimuli were presented as a rectangular array of lights with various patterns of 6 lights at the center and, simultaneously, with places indicated by missing lights at the periphery. One of two possible stimuli (warning) started each trial, indicating whether pattern or place recognition should be performed on the following two stimuli. The purposes of the experiment were to localize the sources of the slow magnetic fields equivalent to the CNVs and to address the issue of regional specialization of prefrontal cortical function. Results indicated that the equivalent current dipoles (ECDs) found as solutions for the measured slow fields were indeed localized in the prefrontal cortex of each hemisphere. Also, in the right hemisphere, the source location of the CNVs was dependent on task, which supported the hypothesis of specialization of prefrontal function. The place recognition task was associated with more anterior and inferior CNV sources than the pattern recognition task. Finally, it was observed that ECDs for the warning period CNVs were indistinguishable from those for the test period of the tasks.


Assuntos
Variação Contingente Negativa/fisiologia , Lobo Frontal/fisiologia , Adulto , Feminino , Lobo Frontal/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa
20.
Electroencephalogr Clin Neurophysiol ; 86(5): 344-7, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-7685268

RESUMO

Evoked magnetic fields to randomized infrequent omissions of visual stimuli resulted in a magnetic field pattern over the right hemisphere consistent with a dipolar source and led to localization of this source within the superior temporal sulcus. Previous investigations using implanted microelectrodes, ablation/lesion procedures in monkeys and observations of behavioral anomalies following injury in humans have already indicated the importance of the inferior portions of the temporal lobe in visual processing. However, until now, no method was available to study noninvasively the role of temporal cortex during visual processing.


Assuntos
Potenciais Evocados Visuais/fisiologia , Lobo Temporal/fisiologia , Análise de Variância , Mapeamento Encefálico , Eletroencefalografia , Campos Eletromagnéticos , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Estimulação Luminosa , Lobo Temporal/anatomia & histologia
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