Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Sci Instrum ; 87(11): 11E524, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910564

RESUMO

We present the first spectrally resolved measurements of x-rays scattered from cryogenic hydrogen jets in the single photon counting limit. The 120 Hz capabilities of the LCLS, together with a novel hydrogen jet design [J. B. Kim et al., Rev. Sci. Instrum. (these proceedings)], allow for the ability to record a near background free spectrum. Such high-dynamic-range x-ray scattering measurements enable a platform to study ultra-fast, laser-driven, heating dynamics of hydrogen plasmas. This measurement has been achieved using two highly annealed pyrolytic graphite crystal spectrometers to spectrally resolve 5.5 keV x-rays elastically and inelastically scattered from cryogenic hydrogen and focused on Cornell-SLAC pixel array detectors [S. Herrmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 718, 550 (2013)].

3.
Stroke ; 32(4): 836-41, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11283379

RESUMO

UNLABELLED: Background and Purpose-The intima-media thickness (IMT) of the carotid artery is a (morphological) sonographic parameter that depends on the degree of atherosclerosis. In the renal arteries, the value of the (hemodynamic) resistive index (RI) is correlated with the severity of atherosclerosis. In contrast to the well-known IMT, no study has yet applied the carotid RI to estimate generalized atherosclerosis. METHODS: -The SMART atherosclerosis risk score was determined in 157 patients (94 men and 63 women; mean age 63 [range 19 to 80] years) with at least 1 vascular risk factor or a known vascular disease. Duplex sonography of the common carotid (CCA) and internal carotid artery (ICA) was then performed, with determination of IMT and RI. RESULTS: -The mean risk score of all patients was 8.8+/-3.5 (range 1 to 17), the mean IMT value in the CCA was 0.727+/-0.161 mm, the mean RI in CCA was 0.79+/-0.066, and the mean RI in ICA was 0.661+/-0.082. Highly significant correlations were found between the score and IMT CCA and the score and RI ICA (r=0.62, P:<0.0001 and r=0.55, P:<0.0001). The score-RI CCA correlation was much less marked (r=0.354, P:<0.0001). The intraobserver and interobserver agreement was less for IMT than for RI CCA and ICA. The areas under the curve of the receiver operating curves to distinguish between low-risk and high-risk patients resulted in values of 0.86, 0.81, and 0.69 for IMT, RI ICA, and RI CCA, respectively. CONCLUSIONS: -Although RI reflects the atherosclerotic process in an indirect manner, the correlation between the RI ICA and the SMART atherosclerosis score as well as the ability to distinguish between low- and high-risk patients are comparable to those of the well-known IMT.


Assuntos
Arteriosclerose/diagnóstico , Artérias Carótidas/fisiopatologia , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Resistência Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Túnica Íntima/patologia , Túnica Média/patologia , Ultrassonografia Doppler
4.
Ultraschall Med ; 21(5): 199-205, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11126599

RESUMO

AIM: We analysed factors influencing diagnostic yield and treatment and their potential for optimising the use of carotid duplex sonography (CDS). METHOD: Patients referred for CDS were divided into three groups: 1: high likelihood of carotid symptoms, 2: suspected presence of asymptomatic carotid lesions, 3: other indications. Clinical data, the grading of stenosis and the therapeutic consequences were analysed. The efficiency of diagnosis was tested with an algorithm. RESULTS: 344 patients were included. Groups 1, 2 and 3 contained > or = 1 pathological finding in the carotid or vertebral system in 68%, 86% and 55% respectively, whereas high-grade stenoses or occlusions of the internal carotid artery (ICA) were detected in 10.8%, 16% and 3.6% respectively. Age > 50, > 1 risk factor, carotid murmur and concomitant vascular disease were associated with a significantly higher diagnostic yield. Subsequent treatment in groups 1, 2 and 3 involved carotid thromboendarterectomy in 6.4%, 2% and 0.7% respectively and the start of treatment with a platelet aggregation inhibitor in 9%, 30% and 17% respectively. The optimisation algorithm would have saved 21% of CDS scans. CONCLUSION: Clinical pre-selection criteria determine the diagnostic yield of CDS. The potential for optimisation depends on the treatment regimen chosen for asymptomatic stenoses and secondary prophylaxis.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Ultrassonografia Doppler Dupla/métodos , Fatores Etários , Algoritmos , Artérias Carótidas/fisiologia , Artérias Carótidas/fisiopatologia , Artéria Carótida Interna/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Risco , Fatores Sexuais , Estatísticas não Paramétricas
5.
Strahlenther Onkol ; 176(6): 259-64, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10897252

RESUMO

BACKGROUND AND PURPOSE: To assess treatment outcome and prognostic factors following postoperative external radiotherapy in 77 patients with low-grade glioma. PATIENTS AND METHODS: Between 1977 and 1996, 45 patients with astrocytoma, 14 with oligodendroglioma and 18 with mixed glioma received postoperative radiotherapy with a median total dose of 52 Gy (range, 45 to 61 Gy). Sixty-seven patients were treated immediately following surgery, 10 patients with tumor progression. The influence of various factors including histology, gender, age, seizures, duration of symptoms (< or = 6 weeks vs > 6 weeks), CT pattern (enhancement vs no enhancement), type of surgery, total radiotherapy dose and timing of radiotherapy on relapse-free survival and overall survival was investigated. RESULTS: The median overall survival time was 81 months, the 5- and 10-year survival rates were 54% and 31%, respectively. The median time to progression was 56 months, while the 5- and 10-year progression-free survival rates were 45% and 24%. Univariate analyses identified the total radiotherapy dose (p = 0.01), duration of symptoms (p = 0.05), the presence of seizures (p = 0.04), and the CT pattern following intravenous contrast (p = 0.005) as significant prognostic factors for overall survival. Progression-free survival rates were influenced by the total dose (p = 0.04), the duration of symptoms (p = 0.01) and CT pattern (p = 0.006). On multivariate analysis, only the CT pattern (enhancement vs no enhancement) remained as independent prognostic factors for both progression-free survival and overall survival. CONCLUSIONS: A minimum total dose of 52 Gy is recommended for the postoperative radiotherapy in low-grade glioma. Tumors with CT enhancement seem to need further intensification of treatment.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Glioma/radioterapia , Glioma/cirurgia , Adulto , Neoplasias Encefálicas/mortalidade , Terapia Combinada , Intervalo Livre de Doença , Feminino , Glioma/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Dosagem Radioterapêutica , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo
6.
Schweiz Med Wochenschr ; 129(10): 410-2, 1999 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-10212975

RESUMO

New microvascular findings in a woman with Parkinson's disease and lower leg oedema are presented. Microlymphography showed enhanced filling of the microlymphatic network with the fluorescent contrast medium comparable to the findings in lymphoedema. The microlymphatic and interstitial pressures of the skin were increased (27 mm Hg and 16 mm Hg respectively). The increased interstitial and microlymphatic pressures are the result of insufficient venous and lymphatic drainage due to impairment of calf muscle function during walking in Parkinson's disease. Manual lymph drainage and compression therapy, in combination with improvement of calf muscle function, resulted in regression of the oedema.


Assuntos
Linfedema/fisiopatologia , Doença de Parkinson/fisiopatologia , Idoso , Espaço Extracelular/fisiologia , Feminino , Humanos , Perna (Membro) , Sistema Linfático/fisiopatologia , Linfedema/complicações , Linfografia/métodos , Doença de Parkinson/complicações , Pressão
7.
Schweiz Med Wochenschr ; 125(17): 846-53, 1995 Apr 29.
Artigo em Alemão | MEDLINE | ID: mdl-7740295

RESUMO

The value of the PCR for CMV in the CSF was evaluated. 23 samples from 20 patients were examined for CMV DNA, of which 11 were positive and 12 were negative for CMV. The clinical spectrum of the patients with positive samples included encephalitis, encephalitis, and polyradiculopathy, or isolated polyradiculopathy. The main symptoms were fever, confusion, lethargy, cognitive disturbance, cranial neuropathy, weakness of the legs, and incontinence. The laboratory evaluation showed a low CD4 lymphocyte count, a slightly increased blood sedimentation rate and a large variation of CSF patterns. The CMV early antigen tests were negative in all cases. In 4 cases the neuroradiological examination was compatible with CMV infection. 8 patients were treated with ganciclovir or foscarnet. Improvement of symptoms was observed in 2 cases and stabilization in 2 others. However, the CMV infection was rapidly progressive and 9 out of 10 patients died after a mean of 53 days after diagnosis.


Assuntos
Complexo AIDS Demência/virologia , Infecções por Citomegalovirus/virologia , Citomegalovirus/genética , DNA Viral/isolamento & purificação , Adulto , Infecções por Citomegalovirus/tratamento farmacológico , Encefalite Viral/virologia , Foscarnet/uso terapêutico , Ganciclovir/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polirradiculoneuropatia/virologia
8.
Schweiz Med Wochenschr ; 122(42): 1582-5, 1992 Oct 17.
Artigo em Alemão | MEDLINE | ID: mdl-1411418

RESUMO

We present a case of sarcoidosis-associated severe thrombocytopenia, a rare but well known complication. Diagnosis of sarcoidosis was based on radiologically enlarged hilar and mediastinal lymph nodes and on histology of biopsies taken from them by mediastinoscopy. In most cases an autoimmune etiology is assumed and platelet-associated antibodies can be demonstrated. Therapy resembles that of chronic idiopathic thrombocytopenia; an early start, sufficient duration and slow reduction of the corticosteroid medication is crucial. If bleeding complications occur, high-dose human gamma-globulins are indicated. In the light of the literature the pathophysiological, diagnostic and therapeutic aspects of this potentially lethal complication are discussed.


Assuntos
Pneumopatias/complicações , Sarcoidose/complicações , Trombocitopenia/complicações , Adulto , Feminino , Humanos , Imunoterapia/métodos , Prednisona/uso terapêutico , Sarcoidose/diagnóstico , Sarcoidose/tratamento farmacológico , Trombocitopenia/tratamento farmacológico , Trombocitopenia/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...