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1.
Scand J Med Sci Sports ; 28(4): 1397-1403, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29239051

RESUMEN

The aim of the study was to evaluate the diagnostic accuracy of carotid ultrasound (CU) to predict coronary atherosclerosis in asymptomatic male marathon runners. A total of 49 male marathon runners older than 45 years (mean age 53.3 ± 7.2 years, range 45-74 years) received CU and cardiac CT angiography (CTA) including calcium scoring (CS). Results of CU and CTA were classified binary: 1. Absence of atherosclerosis and 2. Presence of atherosclerosis. The extent of atherosclerosis was not primary end point of the study. Mean PROCAM score was 2.3% (SD 2.2, range 0.44%-12.34%). One person had to be excluded from analysis (one missing CT-scan). From the remaining 48 marathon runners, 17 (35.4%) had carotid atherosclerosis and 22 (45.8%) coronary atherosclerosis. Atherosclerosis in either exam was diagnosed in 27/48 (56.3%) marathon runners. Diagnostic accuracy of CU to predict coronary atherosclerosis was: sensitivity 54.55% (95% CI 32.2-75.6), specificity 80.8% (CI 60.6-93.4), positive predictive value 70.6 (CI 44.1-89.9), negative predictive value 67.7 (CI 48.6-83.3) with a positive likelihood ratio of 2.84 (CI 1.18-6.82) and a negative likelihood ratio of 0.56 (CI 0.34-0.92). Coronary and/or carotid atherosclerosis can be detected in more than 50% of male marathon runners aged older than 45 years. The diagnostic value of carotid ultrasound to predict coronary atherosclerosis is low but higher than the accuracy of rest- or stress-ECG. As outcome studies in sportsmen are still missing, the routine evaluation of the carotid arteries by ultrasound or even cardiac CT cannot be recommended at present. Furthermore, the incidence of atherosclerosis by our method in normal population is not known.


Asunto(s)
Enfermedades de las Arterias Carótidas/diagnóstico , Enfermedad de la Arteria Coronaria/diagnóstico , Carrera , Enfermedades Asintomáticas , Atletas , Arterias Carótidas/diagnóstico por imagen , Angiografía Coronaria , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Ultrasonografía
2.
Rev Sci Instrum ; 88(11): 113113, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29195371

RESUMEN

CAT-ACT-the hard X-ray beamline for CATalysis and ACTinide/radionuclide research at the KIT synchrotron radiation facility ANKA-is dedicated to X-ray spectroscopy, including "flux hungry" photon-in/photon-out and correlative techniques and combines state-of-the-art optics with a unique infrastructure for radionuclide and catalysis research. Measurements can be performed at photon energies varying between 3.4 keV and 55 keV, thus encompassing the actinide M- and L-edge or potassium K-edge up to the K-edges of the lanthanide series such as cerium. Well-established X-ray absorption fine structure spectroscopy in transmission and fluorescence detection modes is available in combination with high energy-resolution X-ray emission spectroscopy or X-ray diffraction techniques. The modular beamline design with two alternately operated in-line experimental stations enables sufficient flexibility to adapt sample environments and detection systems to many scientific challenges. The ACT experimental station focuses on various aspects of nuclear waste disposal within the mission of the Helmholtz association to contribute to the solution of one of the greatest scientific and social challenges of our time-the safe disposal of heat producing, highly radioactive waste forms from nuclear energy production. It augments present capabilities at the INE-Beamline by increasing the flux and extending the energy range into the hard X-ray regime. The CAT experimental station focuses on catalytic materials, e.g., for energy-related and exhaust gas catalysis. Characterization of catalytically active materials under realistic reaction conditions and the development of in situ and operando cells for sample environments close to industrial reactors are essential aspects at CAT.

3.
Rofo ; 187(7): 561-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25831468

RESUMEN

PURPOSE: To evaluate the prevalence of coronary artery disease (CAD) in middle-aged, male marathon runners using coronary dual source CT angiography (DSCTA). MATERIALS AND METHODS: 50 male marathon runners older than 45 years (mean age: 52.7, standard deviation: 5.9 years, range: 45 to 67 years) received DSCTA including calcium scoring (CS) in addition to standard pre-participation screening. Based on standard risk factors, the risk for coronary events was calculated using the PROCAM score. Coronary status was defined using the following system: 1. absence of CAD (CS zero, no coronary plaques) 2. mild coronary atherosclerosis (CS > 0, coronary plaques with luminal narrowing < 50 %), 3. moderate coronary atherosclerosis (CS > 0, luminal narrowing > 50 %), 4. significant CAD (CS > 0, luminal narrowing > 75 %). RESULTS: The mean PROCAM score was 1.85 % (standard deviation = 1.56, range 0.39 to 8.47 %). 26/50 marathon runners had no atherosclerosis. 1 of the remaining 24 participants had significant CAD, 3 had moderate coronary atherosclerosis and 20 had mild coronary atherosclerosis. Treadmill exercise testing was unremarkable in terms of myocardial ischemia in all participants. Age, systolic blood pressure, personal minimum time, family history of cardiovascular disease and PROCAM score were factors associated with an increased risk for coronary atherosclerosis. CONCLUSION: Coronary atherosclerosis can be detected in almost 50 % of male marathon runners aged older than 45 years. In 24 % of the participants plaques were located in the proximal coronary system. However, only a minority of these persons have obstructive CAD. As expected, treadmill exercise testing failed to detect these persons that possibly have a higher risk for coronary events. KEY POINTS: • Coronary atherosclerosis can be detected in ~50 % of male marathon runners > 45 years. • Only a minority of these persons have obstructive CAD. • Treadmill exercise testing failed to detect these persons. • Cardiac CT might help to identify athletes with elevated risk for coronary events, especially in persons with a family history of coronary artery.


Asunto(s)
Angiografía Coronaria/estadística & datos numéricos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/epidemiología , Carrera/estadística & datos numéricos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Anciano , Alemania/epidemiología , Humanos , Masculino , Salud del Hombre/estadística & datos numéricos , Persona de Mediana Edad , Prevalencia , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad
4.
Rofo ; 186(6): 591-7, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24756426

RESUMEN

PURPOSE: To evaluate a novel monoenergetic post-processing algorithm (MEI+) in patients with poor intrahepatic contrast enhancement. MATERIALS AND METHODS: 25 patients were retrospectively included in this study. Late-phase imaging of the upper abdomen, which was acquired in dual-energy mode (100/140 kV), was used as a model for poor intrahepatic contrast enhancement. Traditional monoenergetic images (MEI), linearly weighted mixed images with different mixing ratios (MI), sole 100 and 140 kV and MEI+ images were calculated. MEI+ is a novel technique which applies frequency-based mixing of the low keV images and an image of optimal keV from a noise perspective to combine the benefits of both image stacks. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the intrahepatic vasculature (IHV) and liver parenchyma (LP) were objectively measured and depiction of IHV was subjectively rated and correlated with portal venous imaging by two readers in consensus. RESULTS: MEI+ was able to increase the SNR of the IHV (5.7 ±â€Š0.4 at 40keV) and LP (4.9 ±â€Š1.0 at 90keV) and CNR (2.1 ±â€Š0.6 at 40keV) greatly compared to MEI (5.1 ±â€Š1.1 at 80keV, 4.7 ±â€Š1.0 at 80keV, 1.0 ±â€Š0.4 at 70keV), MI (5.2 ±â€Š1.1 M5:5, 4.8 ±â€Š1.0 M5:5, 1.0 ±â€Š3.5 M9:1), sole 100 kV images (4.4 ±â€Š1.0, 3.7 ±â€Š0.8, 1.0 ±â€Š0.3) and 140 kV images (2.8 ±â€Š0.5, 3.1 ±â€Š0.6, 0.1 ±â€Š0.2). Subjective assessment rated MEI+ of virtual 40 keV superior to all other images. CONCLUSION: MEI+ is a very promising algorithm for monoenergetic extrapolation which is able to overcome noise limitations associated with traditional monoenergetic techniques at low virtual keV levels and consequently does not suffer from a decline of SNR and CNR at low keV values. This algorithm allows an improvement of IHV depiction in the presence of poor contrast. KEY POINTS: • The evaluated new image-based algorithm for virtual monoenergetic imaging allows calculating low virtual keV images from dual energy datasets with significantly improved contrast-to-noise ratios. • The image based novel monoenergetic extrapolation algorithm applies frequency-based mixing of the low keV images and an image of optimal keV from a noise perspective to combine the benefits of both image stacks.• When compared to traditional monoenergetic images, the novel monoenergetic algorithm has improved contrast-to-noise ratios for both low and high virtual keV images.• Contrast-enhanced dual energy images with poor contrast conditions can be significantly improved, e.g. late phase imaging of the liver.


Asunto(s)
Algoritmos , Venas Hepáticas/diagnóstico por imagen , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Enfermedades Renales/diagnóstico por imagen , Hepatopatías/diagnóstico por imagen , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Programas Informáticos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Yopamidol/análogos & derivados , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Relación Señal-Ruido
5.
Eur J Radiol ; 82(10): 1776-82, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23820177

RESUMEN

INTRODUCTION: Aim of our study was to evaluate, whether myocardial ischemia or myocardial infarction (MI) depicted by myocardial stress perfusion MR imaging (SP CMR) can predict the clinical outcome in patients with coronary artery disease (CAD). MATERIALS AND METHOD: 220 patients were included. Myocardial perfusion was assessed at stress and at rest, using a 2D saturation recovery gradient echo sequence (SR GRE) and myocardial viability by late gadolinium enhancement magnetic resonance images (LGE CMR). MR-images were assessed in regard of presence and extent of MI and ischemia. Patients were monitored for major adverse cardiac events (MACE) (monitoring period: 5-7 years). MACE were correlated with the initial results of SP CMR. RESULTS: Ischemia was found in 143 patients, MI in 107 patients. Number of MACE was in patients with normal SP CMR 0 (51 patients), with ischemia 21 (62 patients), with MI 14 (26 patients), with ischemia and MI 52 (81 patients). In all patients with severe MACE (MI, death) and in 63 of those with recurring symptoms LGE CMR revealed MI at baseline. CONCLUSION: Negative SP CMR indicates low risk for MACE. In patients with stress induced ischemia, MACE might occur even after myocardial revascularization. The presence of MI proved by LGE CMR is associated with a significantly increased risk for MACE.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/cirugía , Prueba de Esfuerzo/estadística & datos numéricos , Angiografía por Resonancia Magnética/estadística & datos numéricos , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/prevención & control , Anciano , Anciano de 80 o más Años , Comorbilidad , Enfermedad de la Arteria Coronaria/mortalidad , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Revascularización Miocárdica , Prevalencia , Pronóstico , Reproducibilidad de los Resultados , Medición de Riesgo , Sensibilidad y Especificidad , Tasa de Supervivencia , Resultado del Tratamiento
6.
Rofo ; 185(12): 1167-74, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23897528

RESUMEN

PURPOSE: Sudden cardiac death [SCD] in competitive athletes is caused by a diverse set of cardiovascular diseases such as hypertrophic and dilated cardiomyopathy [HCM/DCM], myocarditis, coronary anomalies or even coronary artery disease. In order to identify potential risk factors responsible for SCD, elite athletes underwent cardiac magnetic resonance [CMR] imaging. MATERIALS AND METHODS: 73 male [M] and 22 female [F] athletes (mean age 35.2 ±â€Š11.4 years) underwent CMR imaging. ECG-gated breath-hold cine SSFP sequences were used for the evaluation of wall motion abnormalities and myocardial hypertrophy as well as for quantitative analysis (left and right ventricular [LV, RV] end-diastolic and end-systolic volume [EDV, ESV], stroke volume [SV], ejection fraction [EF] and myocardial mass [MM]). Furthermore, left and right atrial sizes were assessed by planimetry and delayed enhancement imaging was performed 10 minutes after the application of contrast agent. Coronary arteries were depicted using free-breathing Flash-3 D MR angiography. RESULTS: The quantitative analyses showed eccentric hypertrophy of the left ventricle (remodeling index [MM/LV-EDV]: M 0.75, F 0.665), enlargement of the RV volumes (RV-EDV: M 122.6 ±â€Š19.0 ml/m², F 99.9 ±â€Š7.2 ml/m²) and an increased SV (LV-SV: M 64.7 ±â€Š10.0 ml/m², F 56.5 ±â€Š5.7 ml/m²; RV-SV; M 66.7 ±â€Š10.4 ml/m², F 54.2 ±â€Š7.1 ml/m²). Abnormal findings were detected in 6 athletes (6.3 %) including one benign variant of coronary anomaly and abnormal late gadolinium enhancement in 2 cases. None of the athletes showed wall motion abnormalities or signs of myocardial ischemia. CONCLUSION: CMR imaging of endurance athletes revealed abnormal findings in more than 5 % of the athletes. However, the prognostic significance remains unclear. Thus, cardiac MRI cannot be recommended as a routine examination in the care of athletes.


Asunto(s)
Atletas , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Cardiopatías/diagnóstico , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Anciano , Gasto Cardíaco/fisiología , Volumen Cardíaco/fisiología , Técnicas de Imagen Sincronizada Cardíacas/métodos , Medios de Contraste/administración & dosificación , Anomalías de los Vasos Coronarios/diagnóstico , Anomalías de los Vasos Coronarios/fisiopatología , Ecocardiografía , Femenino , Atrios Cardíacos/patología , Atrios Cardíacos/fisiopatología , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/fisiopatología , Cardiopatías/fisiopatología , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Angiografía por Resonancia Magnética/métodos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Volumen Sistólico/fisiología , Adulto Joven
7.
Eur Radiol ; 23(2): 588-95, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22898936

RESUMEN

OBJECTIVES: To evaluate stent lumen assessment of various commonly used and newly developed stents for the superficial femoral artery (SFA) using MR angiography (MRA) at 1.5 and 3 T. METHODS: Eleven nitinol stents and one cobalt-chromium stent were compared regarding stent lumen visualisation using a common three-dimensional MRA sequence. Maximum visible stent lumen width and contrast ratio were analysed in three representative slices for each stent type. A scoring system for lumen visualisation was applied. RESULTS: Nitinol stents showed significantly better performance than the cobalt chromium stent (P < 0.05) at 1.5 and 3 T. Maximum visible stent lumen ranged between 43.4 and 95.5 %, contrast ratio between 7.2 and 110.6 %. Regarding both field strengths, seven of the nitinol stents were classified as "suitable". Three nitinol stents were "limited", and one nitinol stent and the cobalt chromium stent were "not suitable". CONCLUSIONS: Intraluminal loss of signal and artefacts of most of the SFA stents do not markedly limit assessment of stent lumen by MRA at 1.5 and 3 T. MRA can thus be considered a valid technique for detection of relevant in-stent restenosis. Applied field strength does not strongly influence stent lumen assessment in general, but proper choice of field strength might be helpful.


Asunto(s)
Aleaciones , Cobalto , Imagenología Tridimensional , Angiografía por Resonancia Magnética/métodos , Stents , Medios de Contraste , Femenino , Arteria Femoral , Humanos , Técnicas In Vitro , Masculino , Ensayo de Materiales , Fantasmas de Imagen , Diseño de Prótesis , Estadísticas no Paramétricas
8.
Radiologe ; 53(1): 45-53, 2013 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-23160570

RESUMEN

CLINICAL/METHODICAL ISSUE: Besides ischemic heart disease cardiomyopathies are common causes of heart failure and sudden cardiac death. STANDARD RADIOLOGICAL METHODS: The diagnostic spectrum in cardiomyopathies comprises non-invasive and invasive examination techniques. METHODICAL INNOVATIONS: The exact verification of certain cardiomyopathies necessitates knowledge of the latest classification of cardiomyopathies as well as dedicated examination protocols. PERFORMANCE: Modern imaging modalities, such as echocardiography and cardiac magnetic resonance imaging (MRI) have emerged as useful imaging tools in the investigation of patients suspected of having many different types of cardiomyopathies. ACHIEVEMENTS: Based on a better understanding of the underlying pathophysiology several diagnostic criteria have been defined using cardiac MRI. In particular there is an increasing importance of cardiac MRI in the description of patients with restrictive and unclassified cardiomyopathies. PRACTICAL RECOMMENDATIONS: Echocardiography still remains the modality of choice in the diagnostics of unclear left ventricular heart failure. Further diagnostic work-up should include cardiac MRI in case of any lack of clarity.


Asunto(s)
Cardiomiopatías/diagnóstico , Aumento de la Imagen/métodos , Imagen por Resonancia Cinemagnética/métodos , Miocardio/patología , Humanos
9.
Abdom Imaging ; 37(2): 244-51, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21479607

RESUMEN

OBJECTIVES: To assess the feasibility of a comprehensive MRI protocol using intrabiliary contrast medium (gadolinium-EOB-DTPA) for evaluation of living liver donors. MATERIAL AND METHODS: In this prospective study, 30 donor candidates for living-related liver transplantation (17 men; 13 women, mean age 37 ± 10.9 years) underwent MRI including MR-angiography (MRA) as well as a conventional T2-weighted MR-cholangiography (MRC) and a contrast-enhanced sequence for depiction of the biliary structures. MRC and MRA images were evaluated for quality on a four-point-scale (score of 0 indicated poor and a score of 3, excellent image quality). Anatomic variants of the arterial, venous, portal venous, and biliary structures were identified. RESULTS: Image quality was diagnostic in all examinations except for 4 of 30 MRA data sets. Intrahepatic biliary structures, especially with regard to the intrahepatic bile ducts of 2nd and 3rd order could be identified with significantly increased image quality than in conventional T2-weighted MRC sequences (P = 0.005 and P = 0.035). A high percentage rate of anatomic variants regarding the biliary, arterial, venous, and portal venous anatomy was found. CONCLUSION: This protocol allows the evaluation of liver donors especially with regard to the biliary structures. However, the depiction of the arterial anatomy requires further technical developments.


Asunto(s)
Trasplante de Hígado , Hígado/anatomía & histología , Donadores Vivos , Imagen por Resonancia Magnética/métodos , Adulto , Pancreatocolangiografía por Resonancia Magnética , Medios de Contraste , Estudios de Factibilidad , Femenino , Gadolinio DTPA , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estadísticas no Paramétricas
10.
J Synchrotron Radiat ; 17(2): 187-92, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20157270

RESUMEN

Mercury (Hg) speciation in different size fractions of a soil sample collected near an industrial area located in the South of Italy, which had been polluted by the dumping of Hg-containing wastes from a chlor-alkali plant, was investigated by XANES spectroscopy. In particular, a special procedure has been developed to study the soil colloidal fraction, both for sample preparation and for XANES data collection. In this soil, Hg was speciated in quite insoluble inorganic forms such as cinnabar (alpha-HgS), metacinnabar (beta-HgS), corderoite (Hg(3)S(2)Cl(2)), and some amorphous Hg, S and Cl-containing species, all derived from the land-disposal of K106 Hg-containing wastes. The contribution of the above-mentioned chemical forms to Hg speciation changed as a function of particle size. For the fraction <2 mm the speciation was: amorphous Hg-S-Cl (34%) > corderoite (26%) > cinnabar (20%) = metacinnabar (20%); for the fraction <2 microm: amorphous Hg-S-Cl (40%) > metacinnabar (24%) > corderoite (20%) > cinnabar (16%); and for the fraction 430-650 nm, where most of the colloidal Hg was concentrated: amorphous Hg-S-Cl (56%) > metacinnabar (33%) > corderoite (6%) > cinnabar (5%). From these data it emerged that, even if Hg was speciated in quite insoluble forms, the colloidal fraction, which is the most mobile and thus the most dangerous, was enriched in relatively more soluble species (i.e. amorphous Hg-S-Cl and metacinnabar), as compared with cinnabar. This aspect should be seriously taken into account when planning environmental risk assessment, since the small particle size in which Hg is concentrated and the changing speciation passing from millimetre to nanometre size could turn apparently safe conditions into more hazardous ones.


Asunto(s)
Coloides/química , Mercurio/química , Contaminantes del Suelo/química , Residuos Industriales/análisis , Italia , Compuestos de Mercurio/química , Espectroscopía de Absorción de Rayos X
11.
J Phys Chem A ; 113(12): 2750-6, 2009 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-19296706

RESUMEN

Sulfur K-edge XANES has been measured for three sulfur model compounds, dibenzothiophene, dibenzothiophene sulfone, and aliphatic sulfur (DL-methionine). The spectra have been simulated with Density Functional Theory (DFT) by using a number of methods, including the half-core-hole approximation. Dipole transition elements were calculated and the transitions were convoluted with linearly increasing Gaussian functions in the first 20 eV of the near-edge region. In the case of dibenzothiophene, relaxation of the first excited states in the presence of the core-hole gave a further improvement. The theoretical results reproduce well the features of the spectra and give insight in the relation between geometric structure and molecular orbitals. Though DL-methionine and dibenzothiophene show a similar sharp rise of the white line, their molecular levels are quite different, pointing out the difficulties in finding useful "fingerprints" in the spectra for specific compounds.


Asunto(s)
Metionina/química , Compuestos de Azufre/química , Tiofenos/química , Modelos Moleculares , Análisis Espectral , Rayos X
12.
Neurodegener Dis ; 4(1): 57-69, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17429220

RESUMEN

The process of developing a successful stroke rehabilitation methodology requires four key components: a good understanding of the pathophysiological mechanisms underlying this brain disease, clear neuroscientific hypotheses to guide therapy, adequate clinical assessments of its efficacy on multiple timescales, and a systematic approach to the application of modern technologies to assist in the everyday work of therapists. Achieving this goal requires collaboration between neuroscientists, technologists and clinicians to develop well-founded systems and clinical protocols that are able to provide quantitatively validated improvements in patient rehabilitation outcomes. In this article we present three new applications of complementary technologies developed in an interdisciplinary matrix for acute-phase upper limb stroke rehabilitation - functional electrical stimulation, arm robot-assisted therapy and virtual reality-based cognitive therapy. We also outline the neuroscientific basis of our approach, present our detailed clinical assessment protocol and provide preliminary results from patient testing of each of the three systems showing their viability for patient use.


Asunto(s)
Terapia Cognitivo-Conductual/métodos , Conducta Cooperativa , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/psicología , Terapia Asistida por Computador/métodos , Adulto , Anciano , Brazo/inervación , Brazo/fisiopatología , Encéfalo/irrigación sanguínea , Encéfalo/patología , Estimulación Eléctrica/métodos , Femenino , Lateralidad Funcional , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Movimiento/fisiología , Recuperación de la Función , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/fisiopatología , Terapia Asistida por Computador/tendencias , Factores de Tiempo
13.
Spinal Cord ; 43(1): 1-13, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15289804

RESUMEN

STUDY DESIGN: Case series. OBJECTIVES: To evaluate the benefit, shortcomings and acceptance of a new transcutaneous functional electrical stimulation (FES) technology aimed at improving the grasp function in tetraplegic subjects in acute and postacute rehabilitation. SETTING: Spinal cord injury (SCI) centre, university hospital. METHODS: : Subjects (N=11) with complete or incomplete SCI at C4/5-C7 who started FES 1-67 months after their accident were included. Hand function tests, analysis of video recordings and of written documentation of FES sessions, status of muscle strength, and follow-up query were used as outcome measures. RESULTS: Nine subjects used FES as a neuroprosthesis. Eight demonstrated improved grasp function and performance in activities of daily living. In one subject, no benefit from FES was observed. Two other subjects showed improvements in muscle strength and facilitation of active movement with FES. Four subjects successfully integrated FES as neuroprosthesis in everyday life within the rehabilitation centre. Three received the system for home use. The most relevant reasons for stopping the FES application were: (i) improvement of voluntary grasp function, (ii) physical and psychological problems, (iii) no available stimulator for home use, and (iv) insufficient assistance for electrode placement at home. Shortcomings related to the transcutaneous surface technology (eg pain or coactivation of neighbouring muscles) could usually be reduced, or did not limit the efficiency or acceptance of FES. Individually designed digital or analogue control devices were preferred. CONCLUSION: Tetraplegic subjects in acute and postacute rehabilitation can profit from a new transcutaneous FES system with respect to functional use and independence. It can be implemented in the rehabilitation programme for muscle strengthening and facilitation of voluntary activity. For a successful application of FES, there is a need for individual electrode placement, stimulation programmes, and FES control devices.


Asunto(s)
Fuerza de la Mano/fisiología , Traumatismos del Cuello/terapia , Cuadriplejía/terapia , Traumatismos de la Médula Espinal/terapia , Estimulación Eléctrica Transcutánea del Nervio/métodos , Actividades Cotidianas , Adolescente , Adulto , Anciano , Electrodos/normas , Femenino , Servicios de Atención de Salud a Domicilio , Humanos , Masculino , Persona de Mediana Edad , Debilidad Muscular/fisiopatología , Debilidad Muscular/terapia , Músculo Esquelético/fisiopatología , Traumatismos del Cuello/fisiopatología , Dolor/prevención & control , Aceptación de la Atención de Salud , Prótesis e Implantes/tendencias , Cuadriplejía/fisiopatología , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Encuestas y Cuestionarios , Estimulación Eléctrica Transcutánea del Nervio/efectos adversos , Resultado del Tratamiento
14.
Sportverletz Sportschaden ; 17(4): 165-70, 2003 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-14666432

RESUMEN

INTRODUCTION: Patellar tendinopathy causes substantial morbidity in both professional and recreational athletes. There is no consensus about conservative treatment strategies for this condition. METHODS: With the help of the evidence-based medicine method it is estimated whether conservative treatment is appropriate for treating pain in this condition. RESULTS: 5 specialist articles that matched the clinical question were found in medical databases. One article was analyzed for clinical relevance. The evaluation showed that physiotherapeutic treatment of pain in combination with additional iontophoresis is more promising than physiotherapy alone. DISCUSSION: Current evidence suggests that traditional physiotherapy should be combined with additional therapeutic treatment. This requires further randomized prospective, placebo-controlled trials in order to confirm its efficiency. Prognostic effects of treatments should be included into these studies.


Asunto(s)
Artralgia/rehabilitación , Trastornos de Traumas Acumulados/rehabilitación , Medicina Basada en la Evidencia/métodos , Iontoforesis/métodos , Cuidados Paliativos/métodos , Rótula/lesiones , Modalidades de Fisioterapia/métodos , Tendinopatía/rehabilitación , Artralgia/etiología , Artralgia/terapia , Traumatismos en Atletas/complicaciones , Traumatismos en Atletas/rehabilitación , Traumatismos en Atletas/terapia , Ensayos Clínicos como Asunto , Terapia Combinada/métodos , Trastornos de Traumas Acumulados/complicaciones , Trastornos de Traumas Acumulados/terapia , Traumatismos de la Rodilla/complicaciones , Traumatismos de la Rodilla/rehabilitación , Traumatismos de la Rodilla/terapia , Tendinopatía/complicaciones , Tendinopatía/terapia , Resultado del Tratamiento
15.
Fresenius J Anal Chem ; 371(6): 823-30, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11768472

RESUMEN

The chemical processes that occur during sequential extraction of a highly Pb-contaminated soil sample were investigated using XAFS spectroscopy for the identification of the Pb species in the solid residues after each step. The sequential extraction was performed following the procedure described by Salomons and Förstner. It was found that during the sequential extraction serious alteration of the chemical binding forms of the Pb occurs. The most important processes underlying the chemical changes are the re-adsorption of solubilized Pb ions by soil matrix components and the precipitation of insoluble Pb species with anions from the extractant.


Asunto(s)
Artefactos , Plomo/análisis , Contaminantes del Suelo/análisis , Alemania , Microscopía Electrónica de Rastreo , Solubilidad , Espectrometría por Rayos X
16.
Science ; 286(5438): 316-8, 1999 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-10514379

RESUMEN

The plant hormone auxin is transported in a polar manner along the shoot-root axis, which requires efflux carriers such as PIN1. Asymmetric localization of PIN1 develops from a random distribution in Arabidopsis early embryogenesis. Coordinated polar localization of PIN1 is defective in gnom embryos. GNOM is a membrane-associated guanine-nucleotide exchange factor on ADP-ribosylation factor G protein (ARF GEF). Thus, GNOM-dependent vesicle trafficking may establish cell polarity, resulting in polar auxin transport.


Asunto(s)
Factores de Ribosilacion-ADP/metabolismo , Proteínas de Arabidopsis , Arabidopsis/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Transporte de Membrana , Arabidopsis/citología , Arabidopsis/embriología , Arabidopsis/genética , Transporte Biológico , Brefeldino A/farmacología , Membrana Celular/metabolismo , Polaridad Celular , Citosol/metabolismo , Factores de Intercambio de Guanina Nucleótido/química , Factores de Intercambio de Guanina Nucleótido/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Conformación Proteica , Proteínas Recombinantes/metabolismo , Semillas/citología , Semillas/metabolismo , Solubilidad , Fracciones Subcelulares/metabolismo
17.
Neurotoxicol Teratol ; 18(5): 547-54, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8888019

RESUMEN

The effects of a single low alcohol dose (men 0.54 g and women 0.44 g alcohol per kg body weight) were measured by static balance, fine motor activity, and mental performance. In 10 healthy volunteers balance was registered by a temporally and spatially high resolution platform measuring the center of foot pressure and a three-dimensional coordination measurement system. Fine motor activity and mental performance were tested with selected experiments from the NES2 (Neurobehavioral Evaluation System) neuropsychological test battery. Changes of bipedal and monopedal balance could be detected after the alcohol consumption. Neither the fine motor activity nor the mental performance test demonstrated significant effects. Thus, the static balance test proved to be a sensitive, fast, and atraumatic method to identify slight neurotoxic disturbances.


Asunto(s)
Consumo de Bebidas Alcohólicas/fisiopatología , Consumo de Bebidas Alcohólicas/psicología , Actividad Motora , Pruebas Neuropsicológicas , Equilibrio Postural , Adulto , Análisis de Varianza , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Neurotoxinas , Postura , Valores de Referencia
18.
J Urol ; 154(2 Pt 2): 812-5, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7609186

RESUMEN

The aim of our study was to analyze the physical and histological behavior of a second generation collagen (GAX 65*) in the mini-pig bladder, comparing it to the commonly used substance for injection (GAX 35*). GAX 65 is a glutaraldehyde cross-linked bovine collagen with a collagen concentration of 65 mg./ml. This much higher collagen concentration could be achieved due to sophisticated manufacturing technology. In 18 mini-pigs 2 to 4, 1 ml. deposits of GAX 65 and 35, respectively, were implanted into the submucosal space of the surgically opened bladder. The animals were sacrificed at months 1, 2, 4 and 6. The elevation (height equals protrusion of the implant into the bladder) and volume of the implants were measured and calculated immediately after injection and at necropsy. Histology was performed. The GAX 65 implants had a lesser decrease of elevation and volume during the 6-month observation period. Histology showed that the invasion of endogenous fibroblasts into the GAX 35 and 65 implants, and the formation of porcine collagen types I and III were almost identical. Clinically GAX 65 has better elevation properties than GAX 35 although statistical analysis did not show any significant difference (p = 0.07 to 0.25). However, preservation of the volume of the GAX 65 implant was significantly superior (p < or = 0.05) compared to that of GAX 35. Therefore, GAX 65 will most probably prove to be an excellent substance for the endoscopic treatment of vesicoureteral reflux and incontinence in children.


Asunto(s)
Colágeno/análogos & derivados , Prótesis e Implantes , Vejiga Urinaria , Animales , Colágeno/administración & dosificación , Colágeno/farmacocinética , Inyecciones , Membrana Mucosa , Porcinos , Porcinos Enanos , Distribución Tisular , Vejiga Urinaria/patología
19.
Br J Audiol ; 24(4): 235-42, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2224290

RESUMEN

A conventional hearing aid has a frequency response that does not change much at normal listening levels. It is therefore unlikely that optimal speech intelligibility and optimal listening comfort can be obtained simultaneously, or in different listening environments. With a programmable hearing aid with multiple memories the listener can choose between a range of sound pictures, which increases the chance of finding a suitable frequency curve for each listening situation. The programmable hearing aid with eight separate settings stored in eight memories, was compared with personal hearing aids fitted according to the recommendations of the National Acoustic Laboratories (NAL) by 22 experienced hearing aid users. One memory of the programmable hearing aid was initially fitted according to the NAL recommendation. The other memories were programmed to give variations around that recommendation. One aim was to investigate whether the hearing-impaired user took advantage of different frequency responses to achieve listening improvements in acoustically different environments. Another aim was to evaluate the ergonomic and acoustical features of the programmable hearing aid, compared with other well fitted hearing aids. The evaluations were based on comparisons of the test hearing aid to the personal aid for each subject, looking at speech tests, direct paired comparison judgements, sound quality judgements and interviews. A majority of the subjects experienced substantial benefit from being able to use different frequency response curves in different environments. With the test hearing aid the subjects performed better in speech discrimination tests in noise.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Audífonos , Pérdida Auditiva Sensorineural/rehabilitación , Terapia Asistida por Computador , Adulto , Anciano , Umbral Auditivo , Comportamiento del Consumidor , Ambiente , Femenino , Pérdida Auditiva Sensorineural/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Ruido , Pruebas de Discriminación del Habla , Inteligibilidad del Habla , Encuestas y Cuestionarios
20.
Acta Otolaryngol Suppl ; 469: 70-5, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2356739

RESUMEN

A basic problem in hearing-aid fitting is the difficulty in finding one setting optimal to all listening situations that might occur. The objective was to develop a behind-the-ear hearing-aid with a very flexible analog signal processor which is digitally controlled, and a memory with logic, so that the hearing-impaired person can select from eight completely different fittings. To program and adjust this multi-programmable hearing-aid (called MemoryMate) a hearing evaluation and recommendation system (called Master-Fit) has been developed, based on an IBM PS/2 computer. This system offers the dispenser prescriptive fitting methods and performance of real ear measurements. It can be used to manage a client database. Preliminary results from a clinical study conducted in 1988 are presented. The paper also describes the uniqueness of this multi-programmable hearing aid as a powerful new research tool.


Asunto(s)
Audífonos , Programas Informáticos , Anciano , Conversión Analogo-Digital , Diseño de Equipo , Femenino , Pérdida Auditiva Sensorineural/rehabilitación , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Discriminación del Habla
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