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1.
Opt Express ; 25(13): 14892-14899, 2017 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-28789071

RESUMEN

We investigate the average power scaling of two diode-pumped Yb-doped fiber amplifiers emitting a diffraction-limited beam. The first fiber under investigation with a core diameter of 30 µm was able to amplify a 10 W narrow linewidth seed laser up to 2.8 kW average output power before the onset of transverse mode instabilities (TMI). A further power scaling was achieved using a second fiber with a smaller core size (23µm), which allowed for a narrow linewidth output power of 3.5 kW limited by stimulated Brillouin scattering (SBS). We mitigated SBS using a spectral broadening mechanism, which allowed us to further increase the output power to 4.3 kW only limited by the available pump power. Up to this power level, a high slope efficiency of 90% with diffraction-limited beam quality and without any sign of TMI or stimulated Raman scattering for a spectral dynamic range of higher than -80 dB was obtained.

2.
Eur Radiol ; 27(12): 5146-5157, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28631080

RESUMEN

OBJECTIVE: To compare cardiac left ventricular (LV) parameters in simultaneously acquired hybrid fluorine-18-fluorodeoxyglucose ([18F] FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with residual tracer activity of upstream PET/CT. METHODS: Twenty-nine patients (23 men, age 58±17 years) underwent cardiac PET/MRI either directly after a non-cardiac PET/CT with homogenous cardiac [18F] FDG uptake (n=20) or for viability assessment (n=9). Gated cardiac [18F] FDG PET and cine MR sequences were acquired simultaneously and evaluated blinded to the cross-imaging results. Image quality (IQ), end-diastolic (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF) and myocardial mass (LVMM) were measured. Pearson correlation and intraclass correlation coefficient (ICC), regression and a Bland-Altman analysis were assessed. RESULTS: Except LVMM, volumetric and functional LV parameters demonstrated high correlations (LVESV: r=0.97, LVEDV: r=0.95, LVEF: r=0.91, LVMM: r=0.87, each p<0.05), but wide limits of agreement (LOA) for LVEDV (-25.3-82.5ml); LVESV (-33.1-72.7ml); LVEF (-18.9-14.8%) and LVMM (-78.2-43.2g). Intra- and interobserver reliability were very high (ICC≥0.95) for all parameters, except for MR-LVEF (ICC=0.87). PET-IQ (0-3) was high (mean: 2.2±0.9) with significant influence on LVMM calculations only. CONCLUSION: In simultaneously acquired cardiac PET/MRI data, LVEDV, LVESV and LVEF show good agreement. However, the agreement seems to be limited if cardiac PET/MRI follows PET/CT and only the residual activity is used. KEY POINTS: • [ 18 F] FDG PET-MRI is feasible with residual [ 18 F] FDG activity in patients with homogenous cardiac uptake. • Cardiac volumes and function assessed by PET/MRI show good agreement. • LVEDV and LVESV are underestimated; PET overestimates LVMM and LVEF. • Cardiac PET and MRI data correlate better when acquired simultaneously than sequentially. • PET and MRI should not assess LV parameters interchangeably.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía de Emisión de Positrones/métodos , Volumen Sistólico , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
3.
Opt Express ; 24(6): 6011-20, 2016 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-27136795

RESUMEN

We report on a newly designed and fabricated ytterbium-doped large mode area fiber with an extremely low NA (~0.04) and related systematic investigations on fiber parameters that crucially influence the mode instability threshold. The fiber is used to demonstrate a narrow linewidth, continuous wave, single mode fiber laser amplifier emitting a maximum output power of 3 kW at a wavelength of 1070 nm without reaching the mode-instability threshold. A high slope efficiency of 90 %, excellent beam quality, high temporal stability, and an ASE suppression of 70 dB could be reached with a signal linewidth of only 170 pm.

4.
Laryngorhinootologie ; 95(10): 674-683, 2016 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-27764854

RESUMEN

Objective: The diagnosis of cancer in pregnancy is rare, but might become more relevant even for head and neck cancer patients due to a shift of age of primipara towards the last third of reproductive years. Unsureness exists about the risk and benefit of diagnostic and therapeutic cancer modalities for the unborn and established recommendations are still missing. But, according to recent data, even multimodal therapeutic approaches (e. g. surgery, radiation, chemotherapy) seem possible in face of pregnancy and should be traded against the risk of prematurity. Material and Methods: Our findings are discussed on the basis of a case report of a pregnant woman with advanced carcinoma of the outer ear canal and therapy options are formulated. Results: Sufficient performed diagnostic modalities do not reach imperilling uterus dosages. A growing number of case reports und studies did not detect any developmental disadvantage of children of prenatal exposed mothers by radiation or chemotherapy, whereas long-term impairments of premature infants are proven. Conclusion: In cancer in pregnancy, an immediate start of well-established therapy modalities like surgery and/or cisplatin-based chemoradiation seems to be possible without unjustifiable risks for the unborn.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia , Neoplasias de Oído, Nariz y Garganta/diagnóstico , Neoplasias de Oído, Nariz y Garganta/terapia , Complicaciones Neoplásicas del Embarazo/diagnóstico , Complicaciones Neoplásicas del Embarazo/terapia , Adulto , Carcinoma de Células Escamosas/patología , Quimioradioterapia Adyuvante/efectos adversos , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Terapia Combinada/efectos adversos , Diagnóstico Diferencial , Femenino , Edad Gestacional , Humanos , Recién Nacido , Imagen por Resonancia Magnética , Estadificación de Neoplasias , Neoplasias de Oído, Nariz y Garganta/patología , Hueso Petroso/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones , Embarazo , Complicaciones Neoplásicas del Embarazo/patología , Dosificación Radioterapéutica , Riesgo , Tomografía Computarizada por Rayos X
5.
Eur Radiol ; 25(2): 575-84, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25316053

RESUMEN

OBJECTIVES: Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM. METHODS: N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR. RESULTS: The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p < 0.05). In the group with good LV-contrast assessment of LV-MM resulted in 147.4 ± 64.8 g in leMDCT vs. 147.1 ± 65.9 in CMR (p > 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p > 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r > 0.9). CONCLUSIONS: LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in > 90% of the cases. KEY POINTS: • LeMDCT of relatively low contrast allows for LV planimetry in HCM. • The correlation of leMDCT-based LV volumetry with gold-standard CMR was excellent (r > 0.9). • LeMDCT requires approximately 2.0mL/kgBW of dye to achieve acceptable contrast.


Asunto(s)
Volumen Cardíaco , Cardiomiopatía Hipertrófica/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Función Ventricular Izquierda , Cardiomiopatía Hipertrófica/patología , Cardiomiopatía Hipertrófica/fisiopatología , Femenino , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Humanos , Imagen por Resonancia Cinemagnética/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Tiempo
6.
Klin Padiatr ; 225(6): 357-61, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24166093

RESUMEN

Since 2007, children and adolescents with Hodgkin lymphomas are treated in the Europe-wide EuroNet-PHL trials. A real time central review process for stratification of the patients enhances quality control and efficient therapy management. This process includes reading of all cross-sectional-images. Since reference evaluation is time critical, a fast, easy to handle and safe data transfer is important. In addition, immediate and constant access to all the data has to be guaranteed in case of queries and for regulatory reasons. To meet the mentioned requirements the EuroNet Paediatric Hodgkin Data Network (funded by the European Union - Project Number: 2007108) was established between 2008 and 2011. A respective tailored data protection plan was formulated. The aim of this article is to describe the networks' mode of operation and the advantages for multi-centre trials that include centralized image review.


Asunto(s)
Ensayos Clínicos como Asunto/estadística & datos numéricos , Redes de Comunicación de Computadores/organización & administración , Sistemas de Administración de Bases de Datos/organización & administración , Diagnóstico por Imagen , Unión Europea , Enfermedad de Hodgkin/terapia , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Sistemas de Información Radiológica/organización & administración , Adolescente , Niño , Seguridad Computacional , Recolección de Datos , Europa (Continente) , Humanos , Control de Calidad
8.
J Environ Radioact ; 186: 90-100, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29056369

RESUMEN

Cryoconites ("cold dust", derived from the Greek) are aeolian sediments accumulated on glacier surfaces. In cryoconites from the surface of the Stubacher Sonnblickkees, a temperate Austrian glacier, extremely high activity concentrations of artificial and natural radionuclides were found. Artificial radionuclides stem from two clearly distinguishable sources, global fallout from the nuclear weapons testing era deposited over a period of years until roughly 1966 and the fallout from Chernobyl in 1986, which was essentially deposited as a single input during one week. Anthropogenic radionuclides identified were 137Cs, 134Cs, 238Pu, 239+240Pu, 90Sr, 241Am, 60Co, 125Sb, 154Eu, and 207Bi. The naturally occurring radionuclides detected were the long-lived radon decay product 210Pb, the primordial radionuclide 4 K and the cosmogenic 7Be. Isotopic ratios of 134Cs/137Cs and 239+240Pu/238Pu were used to separate the nuclide inventory into the contributions of the two aforementioned sources, which show varying degrees of mixing and provide information on the mixing age of the cryoconites. Since isotopic ratios of Pu often have high uncertainties due to low absolute concentrations, age estimation based on this method can be quite inaccurate. Additional information about the age of cryoconites was obtained through analysis of 210Pb, which is constantly deposited over time.


Asunto(s)
Radioisótopos de Cesio/análisis , Cubierta de Hielo/química , Radioisótopos de Plomo/análisis , Plutonio/análisis , Ceniza Radiactiva/análisis , Contaminantes Radiactivos del Agua/análisis
9.
Mol Imaging Biol ; 20(1): 4-20, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28971346

RESUMEN

The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how best to characterise the tumour microenvironment, optimise the complementary information available from PET and MRI, and how advanced data mining and bioinformatics, as well as information from liquid biomarkers (circulating tumour cells and nucleic acids) and pathology, can be integrated to give a more complete characterisation of disease phenotype. Some issues that have dominated previous meetings, such as the accuracy of MR-based attenuation correction (AC) of the PET scan, were finally put to rest as having been adequately addressed for the majority of clinical situations. Likewise, the ability to standardise PET systems for use in multicentre trials was confirmed, thus removing a perceived barrier to larger clinical imaging trials. The meeting openly questioned whether PET/MRI should, in all cases, be used as a whole-body imaging modality or whether in many circumstances it would best be employed to give an in-depth study of previously identified disease in a single organ or region. The meeting concluded that there is still much work to be done in the integration of data from different fields and in developing a common language for all stakeholders involved. In addition, the participants advocated joint training and education for individuals who engage in routine PET/MRI. It was agreed that PET/MRI can enhance our understanding of normal and disrupted biology, and we are in a position to describe the in vivo nature of disease processes, metabolism, evolution of cancer and the monitoring of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.


Asunto(s)
Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Humanos , Biopsia Líquida , Radioterapia Guiada por Imagen , Microambiente Tumoral
10.
Environ Health Insights ; 9(Suppl 1): 41-52, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26005352

RESUMEN

With the increasing awareness of health impacts of particulate matter, there is a growing need to comprehend the spatial and temporal variations of the global abundance of ground-level airborne particulate matter (PM2.5). Here we use a suite of remote sensing and meteorological data products together with ground based observations of PM2.5 from 8,329 measurement sites in 55 countries taken between 1997 and 2014 to train a machine learning algorithm to estimate the daily distributions of PM2.5 from 1997 to the present. We demonstrate that the new PM2.5 data product can reliably represent global observations of PM2.5 for epidemiological studies. An analysis of Baltimore schizophrenia emergency room admissions is presented in terms of the levels of ambient pollution. PM2.5 appears to have an impact on some aspects of mental health.

11.
Mol Imaging Biol ; 17(3): 297-312, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25672749

RESUMEN

This paper summarises the proceedings and discussions at the third annual workshop held in Tübingen, Germany, dedicated to the advancement of the technical, scientific and clinical applications of combined PET/MRI systems in humans. Two days of basic scientific and technical instructions with "hands-on" tutorials were followed by 3 days of invited presentations from active researchers in this and associated fields augmented by round-table discussions and dialogue boards with specific themes. These included the use of PET/MRI in paediatric oncology and in adult neurology, oncology and cardiology, the development of multi-parametric analyses, and efforts to standardise PET/MRI examinations to allow pooling of data for evaluating the technology. A poll taken on the final day demonstrated that over 50 % of those present felt that while PET/MRI technology underwent an inevitable slump after its much-anticipated initial launch, it was now entering a period of slow, progressive development, with new key applications emerging. In particular, researchers are focusing on exploiting the complementary nature of the physiological (PET) and biochemical (MRI/MRS) data within the morphological framework (MRI) that these devices can provide. Much of the discussion was summed up on the final day when one speaker commented on the state of PET/MRI: "the real work has just started".


Asunto(s)
Imagen por Resonancia Magnética/métodos , Imagen Multimodal/métodos , Tomografía de Emisión de Positrones/métodos , Animales , Cardiología/métodos , Alemania , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Oncología Médica/métodos , Neurología/métodos
12.
Transplantation ; 72(2): 216-22, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11477341

RESUMEN

BACKGROUND: Inflammatory leukocyte-endothelium interactions, mediated by selectins, contribute to renal ischemia/reperfusion (I/R) injury. We examined the influence of the soluble P-selectin glycoprotein ligand 1 (sPSGL) on early I/R-induced changes in a rat kidney transplantation model with long cold ischemia. METHODS: After 24 hr of cold storage, syngeneic kidneys were grafted into bilaterally nephrectomized rats. Before transplantation, recipients received either 1 mg/kg of sPSGL or vehicle (n=8 per group). Six hours after reperfusion, grafts were removed for light microscopy and immunohistochemistry. Capillary blood flow was measured under a fluorescence microscope by using the concentric-circles method. RESULTS: A greater proportion, 74.7+/-7.2% (sPSGL) vs. 28+/-7.4% (controls), of all dye-labeled outer medullary capillaries appeared in the 12-microm radius (P<0.01), indicating dense blood flow, whereas 7.6+/-2.9% vs. 43.3+/-9.7%, respectively, appeared in the 60-microm radius (P<0.05), indicating rarefied blood flow. In the sPSGL-treated group, the extent of severe tubular damage within the inner stripe of the outer medulla was lower compared with controls (37.5+/-8.3% vs. 78.4+/-3.5%, P<0.01). Outer medullary heat shock protein 72 expression was 14.5+/-1.6% in the sPSGL-treated group compared with 9.6+/-1.4% in controls (P<0.05). The number of infiltrating polymorphonuclear leukocytes was similar in both groups. Treatment with sPSGL had no influence on the serum creatinine level. CONCLUSIONS: Our data suggest that impairment of outer medullary blood flow is crucial in I/R injury of kidney grafts with prolonged cold storage. Reduction of capillary blood flow perturbations by sPSGL protects tubular cells from severe structural damage. Blocking early selectin-mediated leukocyte adhesion may have therapeutic implications in improving the prognosis of renal transplants with severe I/R injury.


Asunto(s)
Trasplante de Riñón/patología , Riñón , Glicoproteínas de Membrana/uso terapéutico , Selectina-P/fisiología , Daño por Reperfusión/prevención & control , Animales , Proteínas del Choque Térmico HSP72 , Proteínas de Choque Térmico/análisis , Proteínas de Choque Térmico/genética , Riñón/irrigación sanguínea , Corteza Renal/patología , Médula Renal/patología , Trasplante de Riñón/métodos , Trasplante de Riñón/fisiología , Túbulos Renales/patología , Ligandos , Masculino , Microcirculación/efectos de los fármacos , Microcirculación/fisiología , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Neutrófilos/fisiología , Preservación de Órganos , Ratas , Ratas Wistar , Proteínas Recombinantes/uso terapéutico , Factores de Tiempo , Trasplante Isogénico
14.
Nuklearmedizin ; 35(6): 205-11, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8976501

RESUMEN

AIM: This study deals with the effect of the non-uniform attenuation correction method on myocardial tomograms of normal subjects. METHOD: A total of 35 patients (20 female, 15 male) without evidence of cardiac disease underwent SPET with and without attenuation correction using a dual head camera and transmission data obtained by two scanning Gd-153 line sources after administration of 400 MBq Tc-99m-tetrofosmin RESULTS: In non-corrected (NC) stress studies the lowest count rates were found in the inferior segments with mean differences in count rates between maxima and minima of 35.8 +/- 10.8%. In attenuation corrected (AC) images the respective segmental differences averaged only 20.9 +/- 3.3% and the images did not show significant count deficiency in the inferior segments. The effects of correction revealed to be sex dependent, but independent of body mass on average. CONCLUSION: AC using the above technique significantly reduces the variability of count rate distribution in normal subjects and improves the preconditions for accurate diagnostic evaluation of coronary artery disease using SPET.


Asunto(s)
Corazón/diagnóstico por imagen , Tomografía Computarizada de Emisión , Adulto , Dipiridamol , Prueba de Esfuerzo , Femenino , Gadolinio , Corazón/fisiología , Humanos , Masculino , Persona de Mediana Edad , Compuestos Organofosforados , Compuestos de Organotecnecio , Radioisótopos , Valores de Referencia , Reproducibilidad de los Resultados
15.
Nuklearmedizin ; 36(4): 110-6, 1997 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-9289696

RESUMEN

AIM: This present study deals with the question whether normal distribution of local cerebral blood flow (ICBF) agents in adults can be transferred to the age group of 4 to 15 years old children. METHODS: 23 children (age: 4-15 years, mean 11 +/- 3 y) (group I) and 10 adults (age: 27-56 years, mean 45 +/- 10 y) (group II) without evidence of cerebrovascular disease or other brain diseases underwent Tc-99m-ECD-SPECT imaging. Counts in the cortical ROIs were related to those of cerebellar ROIs (= 100%). RESULTS: In group I, relative cortical activity exceeded that of group II, particularly in parietal (107.6 +/- 9.8 vs. 84.1 +/- 12.4%), frontal (97.7 +/- 6.7 vs. 79.4 +/- 8.9%), left temporal areas (99.7 +/- 7.4 vs. 84.9 +/- 10.1%) and in the singular cortex (112.1 +/- 9.1 vs. 95.9 +/- 10.1%, p < 0.05). Cerebral activity uptake/injected dose/acquisition period was linearly correlated with age in group I (r = -0.78, p < 0.001). There was also a correlation of the relative local count density with age in 5 parietal ROIs (r = -0.42 to -0.57), in 2 frontal ROIs (r = -0.48), in 7 temporal ROIs (r = -0.42 to -0.58) and in 2 occipital ROIs (r = -0.44). In 14 cortical regions relative counts differed when subgroups of children aged 4-10 and 11-15 years were analysed. CONCLUSION: There are systematic differences between 4 to 15 years old children and adults regarding the normal distribution of ICBF. Diagnostic use of perfusion agents has to consider the respective age-adjusted normal flow maps; respective normal ranges should be determined for age groups of 4-10 and of 11-15 years separately.


Asunto(s)
Envejecimiento/fisiología , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Cisteína/análogos & derivados , Compuestos de Organotecnecio/farmacocinética , Adolescente , Adulto , Encéfalo/metabolismo , Circulación Cerebrovascular , Niño , Preescolar , Cisteína/farmacocinética , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Especificidad de Órganos , Radiofármacos , Flujo Sanguíneo Regional , Análisis de Regresión , Tomografía Computarizada de Emisión de Fotón Único
16.
Eur J Med Res ; 1(12): 575-81, 1996 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-9438166

RESUMEN

OBJECTIVE: The purpose of our study was to evaluate the predictive power of early postinfarction stress testing in survivors of uncomplicated MI treated with thrombolytics. METHODS: The study population consisted of 102 consecutive, thrombolyzed survivors (56 +/- 11 years) of acute, transmural myocardial infarction with uncomplicated postinfarction course. All patients were clinically stable in the postinfarction period and underwent cycle ergometry, 99mTc perfusion scintigraphy and dobutamine stress-echocardiography within three weeks after the acute event. Coronary angiography was used to determine the extent of CAD, LV ejection fraction (LVEF), TIMI grade and residual stenosis of the infarct-related coronary artery. A follow up questionnaire was performed one year after hospital discharge to determine the relation to the occurrence of cardiac events (unstable angina, reinfarction, PTCA, bypass surgery and death). RESULTS: 30 patients developed 34 cardiac events. Four patients died. Two thirds of the 'cardiac events' in the year of follow-up were revascularization procedures mostly selected by evidence of ischemia on 99mTc perfusion scintigraphy and/or stress-echocardiography. These two methods were significantly associated with the development of new cardiac events (stress-echocardiography: p < 0.01; 99mTc perfusion scintigraphy: p < 0.006). Parameters of bicycle ergometry and variables of coronary angiography were not related to an increased risk of future cardiac events. The number of 'hard cardiac events'--death or nonfatal AMI--was too small (8%) in these patients who are able to exercise to make statistical comparisons. CONCLUSIONS: The study underlines the necessity of early noninvasive risk assessment to identify patients at a greater risk among survivors of uncomplicated AMI treated with thrombolytics who are clinically stable in the early postinfarction period. PTCA and coronary bypass surgery is performed in one third of these patients selected mostly by evidence of ischemia on 99mTc perfusion scintigraphy and/or stress-echocardiography. Results of bicycle ergometry are of limited value in these patients within the first year after acute myocardial infarction.


Asunto(s)
Prueba de Esfuerzo , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/fisiopatología , Terapia Trombolítica , Angiografía Coronaria , Dobutamina , Ecocardiografía , Femenino , Estudios de Seguimiento , Corazón/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Oportunidad Relativa , Cintigrafía , Recurrencia , Factores de Riesgo , Tasa de Supervivencia , Tecnecio Tc 99m Sestamibi , Factores de Tiempo , Resultado del Tratamiento
17.
Eur J Med Res ; 1(9): 446-52, 1996 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-9353245

RESUMEN

The intention of the study was to intraindividually compare the ischemic yield of three stress tests early after acute myocardial infarction. At a large community hospital 107 stable patients who survived acute transmural myocardial infarction after thrombolytic therapy followed by an individual optimized medical treatment, were prospectively investigated by three noninvasive stress tests. All patients received bicycle ergometry, 99mTc perfusion scintigraphy and stress-echocardiography within three weeks after the acute event. Each patient underwent diagnostic cardiac catheterization for determination of angiographic data. 99mTc perfusion scintigraphy had the highest rate of positive test results (61%), as compared to bicycle ergometry (32%), stress echocardiography (34%) and stress induced angina in any of the stress tests performed (40%). In 79% of the patients studied, at least one of four ischemic parameters was positive. The combination of bicycle ergometry, stress induced angina and 99mTc perfusion scintigraphy detected myocardial ischemia in 78% of the patients studied. Concordance of at least three positive parameters was seen in only 27%. Intraindividual comparison between positive and negative test results was inconclusive. Only stress-echocardiography versus stress-induced angina showed a moderate agreement (kappa = 0.44). Stress-induced angina was the only ischemic parameter which corresponded to the grade of the residual stenosis of the infarct related coronary artery (p < 0.01) and reduced left ventricular function (p < 0.005). These findings show, that concordance of three common stress tests in detecting myocardial ischemia anywhere in patients after acute transmural myocardial infarction and thrombolytic therapy is poor. Stress-echocardiography and stress inducible angina show a moderate agreement. Follow-up studies of these patients are currently performed to clarify prognostic significance and therapeutic consequences of positive test results in these patients.


Asunto(s)
Prueba de Esfuerzo , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Terapia Trombolítica , Angina de Pecho , Angiografía Coronaria , Dobutamina/uso terapéutico , Ecocardiografía , Femenino , Alemania , Hospitales Comunitarios , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica , Reproducibilidad de los Resultados , Tecnecio Tc 99m Sestamibi
18.
Transplant Proc ; 36(2): 265-6, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15050129

RESUMEN

BACKGROUND: Ischemia-reperfusion injury (IRI) can result in severe organ dys- or nonfunction. Interaction of leukocytes and endothelial cells mediated by E-selectin appears to be a key step for disturbed microcirculation. Therefore we studied gene and protein expression as well as localization of E-selectin during intestinal IRI. METHODS: Intestinal tissue samples were obtained from extracorporeal perfused intestines (cold ischemia time [CIT] 2 or 20 hours, each n = 5) and additionally in intestinal transplanted pigs (CIT 2 or 20 hours, each n = 1). Mucosal damage was graded according to the Chiu classification. E-selectin mRNA was determined by PCR and quantitative RT-PCR. Localization of E-selectin mRNA was performed by in situ hybridization and of the protein by immunohistochemistry. RESULTS: Histologically, mucosal damage occurred during reperfusion and was earlier and more severe after 20 hours of CIT. E-selectin mRNA expression was detected by PCR already after laparotomy and was elevated after reperfusion. Interestingly, mRNA expression was already increased after 20 hours of CIT. E-selectin mRNA was localized to the luminal surface of muscular, submucosal, and mucosal endothelial cells and the protein was detected on submucosal arterial endothelium as early as 2 hours after reperfusion. CONCLUSION: Prolongation of CIT results in more severe mucosal damage during reperfusion, which is associated with protein expression of E-selection that might be used as a marker for activated endothelial cells. Increased E-selectin mRNA at end of 20 hours of CIT might indicate a preactivated state of endothelial cells potentially triggered by bacterial translocation or products.


Asunto(s)
Selectina E/genética , Intestinos/irrigación sanguínea , Intestinos/fisiología , Daño por Reperfusión/genética , Animales , Mucosa Intestinal/irrigación sanguínea , Mucosa Intestinal/patología , Intestinos/trasplante , Isquemia , ARN Mensajero/genética , Porcinos , Transcripción Genética/genética
19.
Transplant Proc ; 36(2): 267-9, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15050130

RESUMEN

BACKGROUND: Intestinal ischemia-reperfusion injury (IRI) represents an exaggerated inflammatory cascade with a complex pathophysiology. IL-2, IL-6, HSP70, and INF-gamma are mediators of the inflammatory process. Therefore, we investigated their kinetics and localization during intestinal IRI. METHODS: Pig intestinal specimens were obtained during cold preservation (cold ischemia time 2 hours) and extracorporeal perfusion. Mucosal damage was graded according to the Chiu classification. MRNA expression was determined by Northern blot (IL-2, IL-6, IFN-gamma) or by quantitative RT-PCR (IL-6, HSP70) and localized by in situ hybridization. RESULTS: Histologically, mucosal damage occurred during reperfusion. Expression of IL-2 mRNA was up-regulated after HTK perfusion and was highest at the start and 7 hours after reperfusion. Expression of IL-6 mRNA increased at 2 hours after reperfusion and HSP70 at 3 hours after reperfusion. IFN-gamma mRNA was expressed after HTK perfusion, with expression of this cytokine increasing to 1 hour after the start of reperfusion, and decreasing thereafter. IL-2 mRNA was localized to endothelial cells (EC) and leukocytes and in close relation to ganglion cells (GC): IL-6 mRNA in EC, smooth muscle cells (SMC), and GC: HSP70 mRNA in EC and SMC; and IFN-gamma mRNA in leukocytes. CONCLUSION: IL-2, IL-6, HSP70, and INF-gamma are parameters of early mRNA expression during intestinal IRI. EC, SMC, leukocytes, and GC have been identified as sources of transcripts that might afford potential targets for intervention strategies to attenuate IRI.


Asunto(s)
Proteínas HSP70 de Choque Térmico/metabolismo , Interleucina-2/metabolismo , Interleucina-6/metabolismo , Intestinos/irrigación sanguínea , Intestinos/patología , Daño por Reperfusión/fisiopatología , Animales , Proteínas HSP70 de Choque Térmico/análisis , Proteínas HSP70 de Choque Térmico/genética , Interleucina-2/análisis , Interleucina-2/genética , Interleucina-6/análisis , Interleucina-6/genética , Mucosa Intestinal/inmunología , Mucosa Intestinal/fisiopatología , ARN Mensajero/genética , Daño por Reperfusión/inmunología , Porcinos , Transcripción Genética
20.
Clin Dysmorphol ; 9(1): 21-4, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10649792

RESUMEN

We report two brothers with mental retardation, lymphoedema of the limbs and facial anomalies. Hennekam et al. (Am J Med Genet 34:593-600; 1989) described four patients with identical signs and intestinal lymphangiectasia. To confirm the diagnosis of Hennekam syndrome we undertook a duodenal biopsy from the older brother which revealed intestinal lymphangiectasia. So far only one patient with Hennekam syndrome and cerebral abnormalities has been described. This patient presented with pachygyria in the parietal area. Cerebral MRI in our two cases revealed small subcortical hyperintensities in both patients and a large cystic lesion in the younger patient probably representing an old media infarction.


Asunto(s)
Anomalías Múltiples/patología , Encéfalo/anomalías , Biopsia , Preescolar , Cara/anomalías , Humanos , Recién Nacido , Discapacidad Intelectual/patología , Linfangiectasia Intestinal/patología , Linfedema/patología , Imagen por Resonancia Magnética , Masculino , Síndrome
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