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1.
Nat Mater ; 19(4): 474, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32047298

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

2.
Nat Mater ; 19(4): 474, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31932673

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

3.
Nat Mater ; 19(3): 317-322, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31873226

RESUMO

The quest to develop materials that enable the manufacture of dimensionally ultra-stable structures for critical-dimension components in spacecraft has led to much research over many decades and the evolution of carbon fibre reinforced polymer materials. This has resulted in structural designs that feature a near-zero coefficient of thermal expansion. However, the dimensional instabilities that result from moisture ingression and release remain the fundamental vulnerability of the matrix, which restricts many applications. Here, we address this challenge by developing a space-qualifiable physical surface barrier that blends within the mechanical properties of the composite, thus becoming part of the composite itself. The resulting enhanced composite features mechanical integrity and a strength that is superior to the underlying composite, while remaining impervious to moisture and outgassing. We demonstrate production capability for a model-sized component for the Sentinel-5 mission and demonstrate such capability for future European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) programmes such as Copernicus Extension, Earth Explorer and Science Cosmic Visions.

4.
Radiologe ; 56(10): 921-938, 2016 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-27600118

RESUMO

Advances in imaging of the female breast have substantially influenced the diagnosis and probably also the therapy and prognosis of breast cancer in the past few years. This article gives an overview of the most important imaging modalities in the diagnosis of breast cancer. Digital mammography is considered to be the gold standard for the early detection of breast cancer. Digital breast tomosynthesis can increase the diagnostic accuracy of mammography and is used for the assessment of equivocal or suspicious mammography findings. Other modalities, such as ultrasound and contrast-enhanced magnetic resonance imaging (MRI) play an important role in the diagnostics, staging and follow-up of breast cancer. Percutaneous needle biopsy is a rapid and minimally invasive method for the histological verification of breast cancer. New breast imaging modalities, such as contrast-enhanced spectral mammography, diffusion-weighted MRI and MR spectroscopy can possibly further improve breast cancer diagnostics; however, further studies are necessary to prove the advantages of these methods so that they cannot yet be recommended for routine clinical use.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Mamografia/métodos , Ultrassonografia Mamária/métodos , Detecção Precoce de Câncer/métodos , Feminino , Humanos
5.
Eur Respir J ; 32(2): 517-21, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18669792

RESUMO

Hypersensitivity pneumonitis (HP) is an immunologically mediated lung disease due to the repetitive inhalation of antigens. Most new cases arise from residential exposures, notably to birds, and are thus more difficult to recognise. The present authors report a 59-yr-old male who complained of dyspnoea and cough while being treated with amiodarone. Pulmonary function tests revealed restriction and obstruction with low diffusing lung capacity for carbon monoxide and partial pressure of oxygen. A high-resolution computed tomography chest scan and bronchoalveolar lavage showed diffuse bilateral ground-glass attenuation and lymphocytic alveolitis, respectively. Initial diagnosis was amiodarone pulmonary toxicity, but because of a rapidly favourable evolution, this diagnosis was questioned. A careful environmental history revealed a close contact with lovebirds shortly before the onset of symptoms. Precipitins were strongly positive against lovebird droppings, but were negative against other avian antigens. The patient was diagnosed with hypersensitivity pneumonitis to lovebirds. Avoidance of lovebirds and steroid treatment led to rapid improvement. The present observation identifies a new causative agent for hypersensitivity pneumonitis and highlights the importance of a thorough environmental history and of searching for precipitins against antigens directly extracted from the patient's environment. These two procedures should allow a more precise classification of some cases of pneumonitis, and thus might avoid progression of active undiagnosed hypersensitivity pneumonitis to irreversible fibrosis or emphysema.


Assuntos
Alveolite Alérgica Extrínseca/diagnóstico , Alveolite Alérgica Extrínseca/etiologia , Pulmão do Criador de Aves/diagnóstico , Pulmão do Criador de Aves/etiologia , Agapornis , Alveolite Alérgica Extrínseca/complicações , Amiodarona/metabolismo , Animais , Antígenos/metabolismo , Pulmão do Criador de Aves/complicações , Gasometria , Tosse , Humanos , Masculino , Pessoa de Meia-Idade , Precipitinas , Radiografia Torácica , Tomografia Computadorizada por Raios X
6.
Physiol Meas ; 37(7): 1146-62, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27328313

RESUMO

Simultaneous electroencephalography (EEG) and magnetoencephalography (MEG) recordings of neuronal activity from epileptic patients reveal situations in which either EEG or MEG or both modalities show visible interictal spikes. While different signal-to-noise ratios (SNRs) of the spikes in EEG and MEG have been reported, a quantitative relation of spike source orientation and depth as well as the background brain activity to the SNR has not been established. We investigated this quantitative relationship for both dipole and patch sources in an anatomically realistic cortex model. Altogether, 5600 dipole and 3300 patch sources were distributed on the segmented cortical surfaces of two volunteers. The sources were classified according to their quantified depths and orientations, ranging from 20 mm to 60 mm below the skin surface and radial and tangential, respectively. The source time-courses mimicked an interictal spike, and the simulated background activity emulated resting activity. Simulations were conducted with individual three-compartment boundary element models. The SNR was evaluated for 128 EEG, 102 MEG magnetometer, and 204 MEG gradiometer channels. For superficial dipole and superficial patch sources, EEG showed higher SNRs for dominantly radial orientations, and MEG showed higher values for dominantly tangential orientations. Gradiometers provided higher SNR than magnetometers for superficial sources, particularly for those with dominantly tangential orientations. The orientation dependent difference in SNR in EEG and MEG gradually changed as the sources were located deeper, where the interictal spikes generated higher SNRs in EEG compared to those in MEG for all source orientations. With deep sources, the SNRs in gradiometers and magnetometers were of the same order. To better detect spikes, both EEG and MEG should be used.


Assuntos
Encéfalo/diagnóstico por imagem , Eletroencefalografia/instrumentação , Epilepsia/diagnóstico por imagem , Magnetoencefalografia/instrumentação , Imagem Multimodal/instrumentação , Simulação por Computador , Eletrodos Implantados , Eletroencefalografia/métodos , Epilepsia/fisiopatologia , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Magnetoencefalografia/métodos , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Imagem Multimodal/métodos , Adulto Jovem
7.
Eur J Cancer ; 39(2): 175-83, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12509949

RESUMO

To date, there are no reliable criteria to identify those patients with melanoma-infiltrated sentinel lymph nodes (SLNs) of the groin who might benefit from an extended lymphadenectomy, including the pelvic lymph nodes. We hypothesised that there are pelvic lymph nodes that receive lymph directly from the primary tumour, thus being at an increased risk for metastasis. In order to determine the frequency of radioactively labelled pelvic lymph nodes and the kinetics of their appearance, we introduce here a combination of dynamic lymphoscintigraphy, single photon emission computed tomography (SPECT) and image fusion of SPECT and pelvic Computed Tomography (CT)-scans. By dynamic lymphoscintigraphy and intraoperative gamma probe detection, superficially located inguinal SLNs (median 2 nodes) could be identified in all of the 51 patients included in this analysis. The histological search for micrometastases was positive in 16 patients (median Breslow thickness of the primary melanoma 2.5 mm). In 29 patients, SPECT and the image fusion technique were additionally performed. Radioactively labelled pelvic lymph nodes were detected in 20 individuals, 6 of them presenting aberrant pelvic SLNs that, on dynamic lymphoscintigraphy, had appeared simultaneously with the superficial SLN(s). Of the 6 patients in whom radioactive pelvic lymph nodes were excised together with the superficial SLN(s), only one had positive superficial SLNs. In this patient, the aberrant pelvic SLN proved to be tumour-positive. In 9 patients, there was no radiotracer uptake in the pelvic lymph nodes at all. Image fusion of SPECT and pelvic CT-scans is an excellent tool to localise exactly the pelvic tumour-draining nodes. The significance of radioactively labelled pelvic lymph nodes for the probability of pelvic metastases should be analysed further.


Assuntos
Linfonodos/diagnóstico por imagem , Melanoma/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pelve , Biópsia de Linfonodo Sentinela/métodos
8.
Neuroscience ; 91(2): 485-92, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10366005

RESUMO

Neuroplasticity has been investigated considering the neuronal growth-associated phosphoprotein as a marker of neuronal adaptive capabilities. In the present work, studying the hippocampal reorganization observed in the epilepsy model induced by pilocarpine, we carried out quantitative western blotting associated with immunohistochemistry to determine the distribution of growth-associated phosphoprotein in the hippocampus of rats in acute, silent and chronic periods of this epilepsy model. The fibers and punctate elements from the inner molecular layer of the dentate gyrus were strongly immunostained in animals killed 5 h after status epilepticus, compared with the same region in control animals. Rats presenting partial seizures showed no alterations in the immunostaining pattern compared with saline-treated animals. The hippocampal dentate gyrus of animals during the seizure-free period and presenting spontaneous recurrent seizures was also characterized by strong growth-associated phosphoprotein immunostaining of fibers and punctate elements in the inner molecular layer, contrasting with the control group. As determined by western blotting analysis, growth-associated phosphoprotein levels increased following status epilepticus and remained elevated at the later time-points, both during the silent period and during the period of chronic recurring seizures. Pilocarpine-treated animals, which did not develop status epilepticus, showed no change in growth-associated phosphoprotein levels, indicating that status epilepticus is important to induce growth-associated phosphoprotein overexpression. The measurement of this overexpression could represent one of the early signals of hippocampal reorganization due to status epilepticus-induced damage.


Assuntos
Giro Denteado/metabolismo , Epilepsias Parciais/metabolismo , Proteína GAP-43/metabolismo , Fosfoproteínas/metabolismo , Pilocarpina/farmacologia , Convulsões/metabolismo , Animais , Giro Denteado/efeitos dos fármacos , Epilepsias Parciais/induzido quimicamente , Imuno-Histoquímica , Masculino , Ratos , Ratos Wistar , Valores de Referência , Convulsões/induzido quimicamente , Fatores de Tempo
9.
Pediatrics ; 104(3 Pt 1): 405-18, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10469763

RESUMO

BACKGROUND: One-third of children diagnosed with autism spectrum disorders (ASDs) are reported to have had normal early development followed by an autistic regression between the ages of 2 and 3 years. This clinical profile partly parallels that seen in Landau-Kleffner syndrome (LKS), an acquired language disorder (aphasia) believed to be caused by epileptiform activity. Given the additional observation that one-third of autistic children experience one or more seizures by adolescence, epileptiform activity may play a causal role in some cases of autism. OBJECTIVE: To compare and contrast patterns of epileptiform activity in children with autistic regressions versus classic LKS to determine if there is neurobiological overlap between these conditions. It was hypothesized that many children with regressive ASDs would show epileptiform activity in a multifocal pattern that includes the same brain regions implicated in LKS. DESIGN: Magnetoencephalography (MEG), a noninvasive method for identifying zones of abnormal brain electrophysiology, was used to evaluate patterns of epileptiform activity during stage III sleep in 6 children with classic LKS and 50 children with regressive ASDs with onset between 20 and 36 months of age (16 with autism and 34 with pervasive developmental disorder-not otherwise specified). Whereas 5 of the 6 children with LKS had been previously diagnosed with complex-partial seizures, a clinical seizure disorder had been diagnosed for only 15 of the 50 ASD children. However, all the children in this study had been reported to occasionally demonstrate unusual behaviors (eg, rapid blinking, holding of the hands to the ears, unprovoked crying episodes, and/or brief staring spells) which, if exhibited by a normal child, might be interpreted as indicative of a subclinical epileptiform condition. MEG data were compared with simultaneously recorded electroencephalography (EEG) data, and with data from previous 1-hour and/or 24-hour clinical EEG, when available. Multiple-dipole, spatiotemporal modeling was used to identify sites of origin and propagation for epileptiform transients. RESULTS: The MEG of all children with LKS showed primary or secondary epileptiform involvement of the left intra/perisylvian region, with all but 1 child showing additional involvement of the right sylvian region. In all cases of LKS, independent epileptiform activity beyond the sylvian region was absent, although propagation of activity to frontal or parietal regions was seen occasionally. MEG identified epileptiform activity in 41 of the 50 (82%) children with ASDs. In contrast, simultaneous EEG revealed epileptiform activity in only 68%. When epileptiform activity was present in the ASDs, the same intra/perisylvian regions seen to be epileptiform in LKS were active in 85% of the cases. Whereas primary activity outside of the sylvian regions was not seen for any of the children with LKS, 75% of the ASD children with epileptiform activity demonstrated additional nonsylvian zones of independent epileptiform activity. Despite the multifocal nature of the epileptiform activity in the ASDs, neurosurgical intervention aimed at control has lead to a reduction of autistic features and improvement in language skills in 12 of 18 cases. CONCLUSIONS: This study demonstrates that there is a subset of children with ASDs who demonstrate clinically relevant epileptiform activity during slow-wave sleep, and that this activity may be present even in the absence of a clinical seizure disorder. MEG showed significantly greater sensitivity to this epileptiform activity than simultaneous EEG, 1-hour clinical EEG, and 24-hour clinical EEG. The multifocal epileptiform pattern identified by MEG in the ASDs typically includes the same perisylvian brain regions identified as abnormal in LKS. When epileptiform activity is present in the ASDs, therapeutic strategies (antiepileptic drugs, steroids, and even neurosurgery) aimed at its control can lead to a significa


Assuntos
Transtorno Autístico/diagnóstico , Encéfalo/fisiopatologia , Epilepsia/diagnóstico , Síndrome de Landau-Kleffner/diagnóstico , Magnetoencefalografia , Transtorno Autístico/fisiopatologia , Criança , Transtornos Globais do Desenvolvimento Infantil/diagnóstico , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Pré-Escolar , Eletroencefalografia , Epilepsia/fisiopatologia , Feminino , Humanos , Síndrome de Landau-Kleffner/fisiopatologia , Masculino , Sono/fisiologia
10.
J Psychiatr Res ; 33(5): 379-87, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10504006

RESUMO

The precise role of testosterone in regulating mood, especially in alleviating depression, remains unclear although converging evidence indicates that androgens may exert antidepressant action. A model that may potentially assist in the clarification of androgen-mediated effects on mood is the study of cryptorchid men who may grow up with varying degrees of testosterone deficiency depending on the time in their life when cryptorchism is corrected. In this report, we describe a rare case of bilateral cryptorchism that did not come to the attention of the physician to implement effective substitution with testosterone until much later in adult life. The patient developed severe and suicidal depression which responded solely to testosterone. In addition, the patient experienced a delayed but accelerated puberty without any adverse events. These observations, although based on a single case, provide strong evidence that testosterone may exert powerful antidepressant action in the absence of concomitant antidepressant agents.


Assuntos
Criptorquidismo/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Testosterona/deficiência , Adulto , Afeto/efeitos dos fármacos , Afeto/fisiologia , Terapia Combinada , Criptorquidismo/diagnóstico , Criptorquidismo/tratamento farmacológico , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/tratamento farmacológico , Identidade de Gênero , Humanos , Injeções Intramusculares , Masculino , Metiltestosterona/administração & dosagem , Metiltestosterona/efeitos adversos , Inventário de Personalidade , Suicídio/psicologia , Testosterona/sangue , Congêneres da Testosterona/administração & dosagem , Congêneres da Testosterona/efeitos adversos , Prevenção do Suicídio
11.
Clin Neurophysiol ; 115(9): 2041-7, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15294206

RESUMO

OBJECTIVE: To investigate some of the reasons why magnetoencephalographic (MEG) spikes are at times not apparent in conventional electroencephalograms (EEG) when the data are co-registered, and to explore to what extent modern EEG analysis methods can improve the yield. METHODS: Seventy seconds of MEG-EEG co-registration on a 122 channel Neuromag system were studied in a 10-year-old boy with Landau-Kleffner syndrome. Twenty-six EEG channels were originally recorded with a left ear reference. The EEG data were subsequently reformatted (BESA) to a variety of montages for the 10-20 and 10-10 electrode array. A 10 s data epoch was compared in detail for concordance between MEG and EEG spikes. To detect the characteristics of hidden low voltage EEG spikes, MEG spikes were averaged and compared with the concomitant averaged EEG spike. RESULTS: While there was an abundance of EEG as well as MEG spikes on the left; definite right-sided spikes were not visible in the EEG. Right hemispheric MEG spikes were, however, plentiful with an average strength of 757 fT. When the individual MEG spikes from the right hemisphere were compared with the corresponding EEG events their amplitude ranged between 24 and 31 microV and were, therefore, indistinguishable from background activity. The majority of them became visible, however, with further sophisticated data analysis. CONCLUSIONS: When the relative merits of MEG versus EEG recordings for the detection of epileptogenic spike are investigated the 10-20 system of electrode placement and conventional methods of EEG analysis do not provide optimal data assessment. The use of the 10-10 electrode array combined with modern methods of digital data analysis can provide better concordance with MEG data.


Assuntos
Eletroencefalografia/métodos , Epilepsia/fisiopatologia , Magnetoencefalografia/métodos , Criança , Eletrodos , Campos Eletromagnéticos , Humanos , Masculino , Couro Cabeludo
12.
Brain Res Bull ; 47(1): 87-93, 1998 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9766394

RESUMO

Phosphorylation of tyrosine residue in proteins is an important modulatory process for membrane transduction and cell signaling and for several cellular functions. The concentration and distribution of phosphotyrosine proteins were analyzed in the hippocampi of rats in the model of epilepsy induced by pilocarpine using Western blotting and immunohistochemistry. The concentration of several phosphotyrosine proteins increased during status epilepticus. During the seizure-free period and the chronic period of this epilepsy model, the hippocampi of rats did not exhibit changes in the expression of these proteins. Immunohistochemistry showed an increased immunoreactivity throughout the hippocampal formation of rats 1 h after status epilepticus that was acutely induced by pilocarpine. Animals killed after 3 h of status epilepticus showed an increased expression of phosphotyrosine in the hippocampal hilus and CA3 regions. After 5 h of status epilepticus, phosphotyrosine immunoreactivity persisted only in the CA3 region. After 12 h of status epilepticus, the hippocampal formation exhibited a normal phosphotyrosine immunostaining, showing that the increased expression of these proteins is related to the acute phase and that several intracellular events could undergo modifications during the status epilepticus induced by pilocarpine.


Assuntos
Hipocampo/efeitos dos fármacos , Pilocarpina/toxicidade , Proteínas Tirosina Quinases/metabolismo , Estado Epiléptico/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Hipocampo/metabolismo , Imuno-Histoquímica , Masculino , Fosforilação , Ratos , Ratos Wistar , Estado Epiléptico/induzido quimicamente
13.
Brain Res Bull ; 47(3): 223-9, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9865854

RESUMO

Systemic administration of pilocarpine (PILO) in adult rat produces acute limbic seizures leading to status epilepticus. Recent studies have shown the activation of mitogen-activated protein kinase (MAPK) cascades during experimentally induced seizures. MAPK activation may be triggered by glutamatergic stimulation and may play a key role in signal transduction pathways. In the present study, immunocytochemistry was used to analyze the spatiotemporal distribution pattern of the MAPK protein and its active form (A-MAPK) following PILO-induced status epilepticus. MAPK and A-MAPK immunoreactivities exhibited different patterns of distribution in the brain of normal and epileptic rats. The saline-treated rats, as well as the animals that received PILO but did not evolve to status epilepticus, showed a weak but selective MAPK immunoreactivity, detected in the hippocampal pyramidal neurons, dentate gyrus, hilus, CA3, CA1, and entorhinal, piriform, and cingulate cortices. A-MAPK immunoreactivity was instead observed only in neurites of the CA3 and hilus and in cells of the entorhinal and piriform cortices. In PILO-treated rats, between 30 and 60 min after status epilepticus there was an increase of the immunoreactivity to both antibodies, which were differently distributed throughout several structures of the limbic system. The immunostaining showed a slight decrease after 5 h of status epilepticus. However, MAPK and A-MAPK immunopositivities decreased markedly after 12 h of status epilepticus, returning almost to the basal expression. These findings are consistent with a spatial and time-dependent MAPK expression in selected limbic structures, and its activation could represent an initial trigger for neuronal modifications that may take part in the mechanism underlying acute epileptogenesis and in long-lasting neuropathological changes of the PILO model of epilepsy.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Sistema Límbico/enzimologia , Estado Epiléptico/enzimologia , Animais , Contagem de Células , Imuno-Histoquímica , Sistema Límbico/patologia , Masculino , Neurônios/enzimologia , Neurônios/patologia , Fosforilação , Ratos , Ratos Wistar , Estado Epiléptico/patologia , Fatores de Tempo , Distribuição Tecidual
14.
J Clin Neurophysiol ; 15(6): 521-8, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9881925

RESUMO

The aim of this study was to compare the topographical quantitative EEG (qEEG) changes induced by nonstandardized hyperventilation and those induced by standardized hyperventilation (with the end-tidal PCO2 being maintained at 2 kPa [15 mm Hg]). We examined 18 healthy volunteers during nonstandardized and 20 during standardized hyperventilation. During nonstandardized hyperventilation, the mean spectral power density in this group significantly increased 1.9 fold within the delta-, 2.2 fold within the theta-, 1.8 fold within the alpha-, and 1.9 fold within the beta-frequency band. There was no significant change of the power ratio and was no topographic difference between 4 frequency bands investigated. During standardized hyperventilation, the mean spectral power density in the group significantly increased to 12.9 fold within the delta-, to 7.6 fold within the theta-, to 1.4 fold within the alpha-, and to 2.4 fold within the beta frequency band. The power ratio decreased significantly. Such a pronounced EEG slowing with delta and theta augmentation was never found during nonstandardized hyperventilation. We conclude that a consistent slowing of the qEEG in all leads including a constant topographical maximum can only be induced by standardized, sufficiently pronounced hyperventilation.


Assuntos
Mapeamento Encefálico , Eletroencefalografia/métodos , Hiperventilação/diagnóstico , Adulto , Feminino , Lobo Frontal/fisiopatologia , Humanos , Masculino , Lobo Occipital/fisiopatologia , Lobo Parietal/fisiopatologia , Lobo Temporal/fisiopatologia , Fatores de Tempo
15.
J Neural Transm Suppl ; 53: 385-98, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9700674

RESUMO

Cerebrolysin, a peptidergic nootropic drug, was to be effective on learning and other cognitive functions in animal experiments as well as in clinical studies. Hyperventilation (HV) as a model of brain ischemia induces slowing of the EEG and cognitive impairment. The aim of this study was to examine the potential dose-dependent effects of Cerebrolysin on HV related EEG changes and short term memory during chronic (10 days) application and the time dependency of these effects. In this single centre, double blind, randomized, placebo-controlled, parallel group study 48 healthy males were enrolled and received either 100 ml placebo (NaCl) or Cerebrolysin (10 ml or 30 ml or 50 ml) in a volume of 100 ml (NaCl) for 10 days. EEG at baseline and during HV as well as the cognitive performance was evaluated at Day 1 (baseline, 15 min p.i., 2 h p.i., 4 h p.i., 8 h p.i., 24 h p.i.), Day 10 (baseline, 15 min p.i., 2 h p.i.,) and at day 11 (24 h. after the last infusion). The main effects found during the study can be summarized as follows: At baseline we found an increase of the EEG power ratio (PR) for the grouptrated with 10 ml Cerebrolysin. The effect was most pronounced at the parietal cortex. The effect started after 15 min, was most expressed at 2 h and was kept until 8 h. During HV we found a relative PR decrease of the group (10 ml Cerebrolysin) at 2 hours. For short term memory, there is a trend towards less effective word recall for the baseline situation during the first 4 hours for the placebo. This effect was not observed in the Cerebrolysin treated groups. If chronic effects are concerned, the PR increased over the parietal regions at 24 h for the groups treated with 10 and 30 ml Cerebrolysin. The effect remains at day 10 and 11. But at 10 and 11 days there was also a trend for a relative increase of the PR in the group treated with 50ml Cerebrolysin. Signs of overdosage occurred with the highest concentrations of Cerebrolysin. The events were only mild and caused no harm to the volunteers. The highest concentration caused a small but significant reduction of blood pressure. The effects could be interpreted as those of an atypical nootropic with anti-ischemic properties.


Assuntos
Aminoácidos/farmacologia , Isquemia Encefálica/psicologia , Eletroencefalografia/efeitos dos fármacos , Hiperventilação/psicologia , Memória de Curto Prazo/efeitos dos fármacos , Nootrópicos/farmacologia , Adulto , Isquemia Encefálica/etiologia , Cognição/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Humanos , Hiperventilação/complicações , Masculino , Desempenho Psicomotor/efeitos dos fármacos
16.
J Physiol Pharmacol ; 42(2): 235-48, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1810304

RESUMO

To investigate whether the sampling theorem was fulfilled up to now in experimental and clinical EEG-mapping of neonates and to determine the "smearing effect" of EEG transmission by the leading media up to the skin, EEG-maps from 5 slightly anaesthetized term newborn piglets and 8 healthy human newborns were calculated. A spatial sampling rate of 1-2 cycles per cm is necessary for a sufficient reproduction of surface EEG topology in newborn piglets showing activity maxima within motor projection zones. In human neonates, 8-channel mapping gave insufficient results, whereas state and EEG pattern related 16-channel maps provided sufficiently constant, but not complete pattern. Simultaneous maps from epidural and epiossal, and epiossal, and surface recordings in newborn piglets showed only small "smearing" effects. We conclude, the more topical interpretation chances exist, like in neonates with smaller "smearing" effects of transmission media, the more complete uptake of original data for mapping is necessary. Up to now, it is done seldomly.


Assuntos
Animais Recém-Nascidos/fisiologia , Eletroencefalografia , Recém-Nascido/fisiologia , Animais , Eletroencefalografia/métodos , Humanos , Estatística como Assunto , Suínos
17.
Br J Radiol ; 71(845): 528-34, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9691898

RESUMO

Contact mammography with current photostimulable storage phosphors is hampered by its low spatial resolution. Detail visualization can be improved by geometric magnification radiography which enlarges small details to exceed inherent image noise. This study compares storage phosphor mammography using a dedicated direct magnification system with state-of-the-art conventional screen-film mammography. Storage phosphor direct magnification survey views (1.7x) and spot views (4x) were obtained with a prototype mammography unit providing focal spot sizes of 120-40 microns. Conventional technique screen-film survey views (1.1x) and spot views (1.8x) served as comparison. A contrast detail study and a receiver operating characteristic (ROC) analysis using an anthropomorphic breast phantom with superimposed microcalcifications was performed. Contrast detail resolution in the digital and conventional survey views were equivalent. For the spot views, contrast detail resolution was significantly higher with the digital technique (p < 0.001). ROC analysis of 400 observations demonstrated a significantly higher performance (p < 0.001) with digital images versus conventional screen-film mammograms. The area under the ROC curve (Az) in the digital survey views was 0.76 +/- 0.07 versus 0.59 +/- 0.02 in the conventional technique. In digital spot views, Az was 0.82 +/- 0.07 as compared with 0.66 +/- 0.04 in the conventional spot views. These results suggest that storage phosphor digital mammography in conjunction with direct geometric magnification technique may be superior to conventional screen-film mammography in the detection of microcalcifications.


Assuntos
Mamografia/métodos , Intensificação de Imagem Radiográfica , Ecrans Intensificadores para Raios X , Doenças Mamárias/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Feminino , Humanos , Imagens de Fantasmas , Curva ROC , Tecnologia Radiológica
18.
Rofo ; 157(2): 145-9, 1992 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-1515623

RESUMO

Measurements of bone density were carried out in 25 patients on dialysis for terminal renal insufficiency, using quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA). Unlike in subjects with normal kidneys, there was no significant correlation between these methods in this series. Ten patients showed an increase in bone density of the vertebral spongiosa on QCT measurements, which was interpreted as due to osteosclerotic bone changes in renal osteopathy. QCT showed advantages over DXA in demonstrating these changes.


Assuntos
Absorciometria de Fóton/métodos , Densidade Óssea , Distúrbio Mineral e Ósseo na Doença Renal Crônica/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Distúrbio Mineral e Ósseo na Doença Renal Crônica/etiologia , Feminino , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Osteosclerose/diagnóstico , Osteosclerose/etiologia , Diálise Renal
19.
Rofo ; 164(1): 25-30, 1996 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-8630356

RESUMO

PURPOSE: A retrospective study was performed in 70 patients with peripheral vascular disease who underwent MR angiography of the lower extremity. MATERIAL AND METHODS: MR angiography was performed with a 2-D-TOF sequence including a travelling presaturation to suppress the venous signal. Postprocessing images were obtained with the MIP algorithm. The MRA results were compared with conventional or digital angiography in all patients. RESULTS: Only 19 stenoses out of 31 which showed a degree of stenosis between 30 and 99% could be visualised by MR angiography. 9 stenoses were correctly classified by MRA. In 9 cases the degree of stenosis was overestimated, in one case it was underestimated. All 56 occlusions were correctly detected. 12 severe stenoses diagnosed with conventional angiography were graded as occlusions with MR angiography. CONCLUSIONS: MR angiography cannot be accepted in preoperative staging of patients with peripheral vascular disease. The postoperative examination seems to be a practical noninvasive alternative.


Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Perna (Membro)/irrigação sanguínea , Angiografia por Ressonância Magnética/métodos , Algoritmos , Angiografia , Angiografia Digital , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Humanos , Estudos Retrospectivos
20.
Rofo ; 170(2): 174-80, 1999 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-10101358

RESUMO

PURPOSE: To investigate if the assessment of spinal fracture stability according to the Magerl classification permits a better therapy decision than using the Denis 3-column model. MATERIAL AND METHODS: The X-ray and CT images of 99 consecutive patients treated for thoracolumbar spine fractures were analysed and the fractures were classified according to the above mentioned classifications. Using the 3-column model, the involvement of two or more columns was considered as unstable, whereas the fracture types A3.2, A3.3, B and C of the Magerl classification were defined as unstable. The stability evaluation was compared with the therapy decision and outcome. RESULTS: According to the 3-column model, 23 of 53 fractures which were classified as unstable were operated. Only five of the 30 conservatively treated unstable fractures showed a reduced healing process. The 46 stable fractures were treated conservatively with good results. Using the Magerl classification, 21 of the 28 unstable fractures were operated and 4 of the remaining 7 cases showed a reduced healing process. Of the 71 stable fractures only 2 were operated and in one patient minimal neurological symptoms occurred. CONCLUSION: The Magerl classification enables a more exact definition of stable and unstable spinal fractures.


Assuntos
Fraturas da Coluna Vertebral/classificação , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/lesões , Vértebras Cervicais/cirurgia , Criança , Feminino , Consolidação da Fratura/fisiologia , Fraturas Cominutivas/classificação , Fraturas Cominutivas/diagnóstico por imagem , Fraturas Cominutivas/cirurgia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/lesões , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/lesões , Vértebras Torácicas/cirurgia , Resultado do Tratamento
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