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BACKGROUND: Hantavirus infection is an uncommon cause of acute renal failure with massive proteinuria. Serology tests to support a presumptive diagnosis usually take a few days. During the initial work-up, autoimmune causes including anti-glomerular basement membrane (GBM) glomerulonephritis need to be excluded, because these require urgent therapy. In this case the delay in serological testing caused a dilemma in treatment initiation. CASE PRESENTATION: An 18-year-old patient was admitted to the hospital with acute renal failure, erythrocyturia and massive proteinuria. Routine blood analysis showed leucocytosis (40,5 × 109/l) and a serum creatinine of 233 µmol/l. Infectious causes, e.g. leptospirosis or hantavirus infection, or an autoimmune disease, e.g., AAV or anti-GBM glomerulonephritis was the most feasible underlying diagnosis. Before hantavirus serology results were known, anti-GBM antibodies were positive. Treatment for anti-GBM glomerulonephritis was withheld, because of the absence of other signs and symptoms of the disease and slight improvement of renal function. The diagnosis of acute hantavirus infection was later on confirmed, by seroconversion of a follow-up serum sample. Without further intervention renal function recovered and anti-GBM antibodies disappeared. CONCLUSION: Hantavirus infection may induce anti-GBM antibodies, falsely suggestive of anti-GBM glomerulonephritis. Anti-GBM antibodies are supposed to be 100% specific. No earlier reports of false positive anti-GBM titers were reported. Nevertheless, the anti-GBM antibodies in this case were seen as an innocent bystander effect. Considering the need of urgent initiation of plasmapheresis and administration of immunosuppressants it may lead to diagnostic dilemmas with crucial therapeutic consequences. Knowledge of this anomaly when diagnosing acute renal failure, is very important.
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Lesión Renal Aguda/sangre , Lesión Renal Aguda/diagnóstico , Autoanticuerpos/sangre , Infecciones por Hantavirus/sangre , Infecciones por Hantavirus/diagnóstico , Orthohantavirus/aislamiento & purificación , Lesión Renal Aguda/etiología , Adolescente , Infecciones por Hantavirus/complicaciones , Humanos , MasculinoRESUMEN
The aim of this study was to investigate the signal-to-noise ratio (SNR) gain in early-stage cervical cancer at ultrahigh-field MRI (e.g. 7 T) using a combination of multiple external antennas and a single endorectal antenna. In particular, we used an endorectal monopole antenna to increase the SNR in cervical magnetic resonance imaging (MRI). This should allow high-resolution, T2 -weighted imaging and magnetic resonance spectroscopy (MRS) for metabolic staging, which could facilitate the local tumor status assessment. In a prospective feasibility study, five healthy female volunteers and six patients with histologically proven stage IB1-IIB cervical cancer were scanned at 7 T. We used seven external fractionated dipole antennas for transmit-receive (transceive) and an endorectally placed monopole antenna for reception only. A region of interest, containing both normal cervix and tumor tissue, was selected for the SNR measurement. Separated signal and noise measurements were obtained in the region of the cervix for each element and in the near field of the monopole antenna (radius < 30 mm) to calculate the SNR gain of the endorectal antenna in each patient. We obtained high-resolution, T2 -weighted images with a voxel size of 0.7 × 0.8 × 3.0 mm3 . In four cases with optimal placement of the endorectal antenna (verified on the T2 -weighted images), a mean gain of 2.2 in SNR was obtained at the overall cervix and tumor tissue area. Within a radius of 30 mm from the monopole antenna, a mean SNR gain of 3.7 was achieved in the four optimal cases. Overlap between the two different regions of the SNR calculations was around 24%. We have demonstrated that the use of an endorectal monopole antenna substantially increases the SNR of 7-T MRI at the cervical anatomy. Combined with the intrinsically high SNR of ultrahigh-field MRI, this gain may be employed to obtain metabolic information using MRS and to enhance spatial resolutions to assess tumor invasion.
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Imagen por Resonancia Magnética/métodos , Recto/diagnóstico por imagen , Relación Señal-Ruido , Neoplasias del Cuello Uterino/diagnóstico por imagen , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Femenino , Humanos , Estadificación de NeoplasiasRESUMEN
Early studies that categorized odontocete pulsed sounds had few means of discriminating signals used for biosonar-based foraging from those used for communication. This capability to identify the function of sounds is important for understanding and interpreting behavior; it is also essential for monitoring and mitigating potential disturbance from human activities. Archival tags were placed on free-ranging Grampus griseus to quantify and discriminate between pulsed sounds used for echolocation-based foraging and those used for communication. Two types of rapid click-series pulsed sounds, buzzes and burst pulses, were identified as produced by the tagged dolphins and classified using a Gaussian mixture model based on their duration, association with jerk (i.e. rapid change of acceleration) and temporal association with click trains. Buzzes followed regular echolocation clicks and coincided with a strong jerk signal from accelerometers on the tag. They consisted of series averaging 359±210 clicks (mean±s.d.) with an increasing repetition rate and relatively low amplitude. Burst pulses consisted of relatively short click series averaging 45±54 clicks with decreasing repetition rate and longer inter-click interval that were less likely to be associated with regular echolocation and the jerk signal. These results suggest that the longer, relatively lower amplitude, jerk-associated buzzes are used in this species to capture prey, mostly during the bottom phase of foraging dives, as seen in other odontocetes. In contrast, the shorter, isolated burst pulses that are generally emitted by the dolphins while at or near the surface are used outside of a direct, known foraging context.
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OBJECTIVE: In chronic fatigue syndrome (CFS), only a few imaging and histopathological studies have previously assessed either cardiac dimensions/function or myocardial tissue, suggesting smaller left ventricular (LV) dimensions, LV wall motion abnormalities and occasionally viral persistence that may lead to cardiomyopathy. The present study with cardiac magnetic resonance (CMR) imaging is the first to use a contrast-enhanced approach to assess cardiac involvement, including tissue characterisation of the LV wall. METHODS: CMR measurements of 12 female CFS patients were compared with data of 36 age-matched, healthy female controls. With cine imaging, LV volumes, ejection fraction (EF), mass, and wall motion abnormalities were assessed. T2-weighted images were analysed for increased signal intensity, reflecting oedema (i. e. inflammation). In addition, the presence of contrast enhancement, reflecting fibrosis (i. e. myocardial damage), was analysed. RESULTS: When comparing CFS patients and healthy controls, LVEF (57.9 ± 4.3 % vs. 63.7 ± 3.7 %; p < 0.01), end-diastolic diameter (44 ± 3.7 mm vs. 49 ± 3.7 mm; p < 0.01), as well as body surface area corrected LV end-diastolic volume (77.5 ± 6.2 ml/m2 vs. 86.0 ± 9.3 ml/m2; p < 0.01), stroke volume (44.9 ± 4.5 ml/m2 vs. 54.9 ± 6.3 ml/m2; p < 0.001), and mass (39.8 ± 6.5 g/m2 vs. 49.6 ± 7.1 g/m2; p = 0.02) were significantly lower in patients. Wall motion abnormalities were observed in four patients and contrast enhancement (fibrosis) in three; none of the controls showed wall motion abnormalities or contrast enhancement. None of the patients or controls showed increased signal intensity on the T2-weighted images. CONCLUSION: In patients with CFS, CMR demonstrated lower LV dimensions and a mildly reduced LV function. The presence of myocardial fibrosis in some CFS patients suggests that CMR assessment of cardiac involvement is warranted as part of the scientific exploration, which may imply serial non-invasive examinations.
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BACKGROUND: Virchow-Robin spaces (VRS) are associated with vascular and neurodegenerative disease. In multiple sclerosis (MS), VRS have been associated with neuroinflammation. Ultra-high field imaging may be used to gain insight in these contradictory findings. OBJECTIVE: The objective of this paper is to analyze VRS in MS patients using high-resolution 7 Tesla (T) MRI. Additionally, we investigated whether the widening of VRS is related to inflammatory or neurodegenerative aspects of MS. METHODS: Thirty-four MS patients and 11 healthy controls were examined at 7T. Number and size of VRS were measured on three-dimensional (3D) T1-weighted images, and 3D fluid-attenuated inversion recovery (FLAIR) images were used for MS lesion detection. Brain atrophy was quantified by computing supratentorial brain volume fraction (sBVF). VRS counts were correlated with clinical variables, lesion count and sBVF. RESULTS: MS patients displayed more VRS (median 11) than healthy controls (median four), p = 0.001. VRS size did not differ between both groups. VRS count in MS patients was associated with sBVF (rho = -0.40, p = 0.02), but not with lesion count (p = 0.22). CONCLUSIONS: The 7T MRI reveals increased numbers of VRS in MS. The finding that VRS are associated with supratentorial brain atrophy, but not with lesion count, suggests that VRS might rather serve as a neurodegenerative than an inflammatory marker in MS.
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Encéfalo/patología , Imagen por Resonancia Magnética/métodos , Esclerosis Múltiple/patología , Enfermedades Neurodegenerativas/patología , Adulto , Atrofia/patología , Biomarcadores , Femenino , Humanos , Imagen por Resonancia Magnética/instrumentación , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/diagnóstico , Enfermedades Neurodegenerativas/diagnósticoRESUMEN
BACKGROUND: In chronic obstructive pulmonary disease (COPD), there is a poor correlation between forced expiratory volume in 1 s (FEV1) and dyspnea following bronchodilator use. Better correlations have been observed between inspiratory lung function parameters (ILPs) and dyspnea, which drives our interest in ILPs. However, the acute and prolonged effects of long-acting bronchodilators and oral corticosteroids on ILPs have not been well investigated. Therefore, the aim of this study was to investigate the effects of these treatments on the ILPs, FEV1, dyspnea (visual analog scale (VAS)) and clinical COPD questionnaire (CCQ). METHODS: Twenty-eight stable COPD patients had their ILPs and FEV1 measured both before and 2 h after the use of a single dose of 18 mcg bronchodilator tiotropium and 50 mcg salmeterol. Thereafter, the patients were randomized to 2 weeks of treatment with 30 mg oral prednisolone once daily or oral placebo in combination with daily treatment with these two bronchodilators. Four weeks after the cessation of the randomized treatment, the ILPs and FEV1 were again measured. After each intervention, any change in the VAS score was assessed. RESULTS: With both bronchodilators, significant improvements in ILPs were demonstrated (p < 0.005), with the exception of changes in ILPs inspiratory capacity (IC) and forced inspiratory flow at 50% of the vital capacity (FIF50) after tiotropium inhalation. After 2 weeks of treatment with prednisolone, significant differences were found for ILP forced inspiratory volume in 1 s (FIV1) and FEV1 compared with placebo. These differences were no longer present 4 weeks after the cessation of prednisolone. Significant relationships between ILPs and VAS scores were only found after 2 weeks of treatment with prednisolone or placebo. CONCLUSIONS: After a single dose of long-acting bronchodilator salmeterol, significant improvements are observed in all ILPs and in FIV1 and PIF after tiotropium. Two weeks of oral corticosteroid treatment improved the FIV1 and FEV1. The dyspnea VAS score was only significantly correlated with the ILPs after 2 weeks of oral corticosteroid treatment.
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Broncodilatadores/farmacología , Disnea/tratamiento farmacológico , Prednisolona/farmacología , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Administración Oral , Anciano , Anciano de 80 o más Años , Albuterol/administración & dosificación , Albuterol/análogos & derivados , Albuterol/farmacología , Albuterol/uso terapéutico , Broncodilatadores/administración & dosificación , Broncodilatadores/uso terapéutico , Preparaciones de Acción Retardada , Método Doble Ciego , Disnea/etiología , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Glucocorticoides/administración & dosificación , Glucocorticoides/farmacología , Glucocorticoides/uso terapéutico , Humanos , Capacidad Inspiratoria/efectos de los fármacos , Masculino , Persona de Mediana Edad , Prednisolona/administración & dosificación , Prednisolona/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Pruebas de Función Respiratoria , Xinafoato de Salmeterol , Derivados de Escopolamina/administración & dosificación , Derivados de Escopolamina/farmacología , Derivados de Escopolamina/uso terapéutico , Encuestas y Cuestionarios , Factores de Tiempo , Bromuro de TiotropioRESUMEN
The assessment of both geometry and hemodynamics of the intracranial arteries has important diagnostic value in internal carotid occlusion, sickle cell disease, and aneurysm development. Provided that signal to noise ratio (SNR) and resolution are high, these factors can be measured with time-resolved three-dimensional phase contrast MRI. However, within a given scan time duration, an increase in resolution causes a decrease in SNR and vice versa, hampering flow quantification and visualization. To study the benefits of higher SNR at 7 T, three-dimensional phase contrast MRI in the Circle of Willis was performed at 3 T and 7 T in five volunteers. Results showed that the SNR at 7 T was roughly 2.6 times higher than at 3 T. Therefore, segmentation of small vessels such as the anterior and posterior communicating arteries succeeded more frequently at 7 T. Direction of flow and smoothness of streamlines in the anterior and posterior communicating arteries were more pronounced at 7 T. Mean velocity magnitude values in the vessels of the Circle of Willis were higher at 3 T due to noise compared to 7 T. Likewise, areas of the vessels were lower at 3 T. In conclusion, the gain in SNR at 7 T compared to 3 T allows for improved flow visualization and quantification in intracranial arteries.
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Algoritmos , Circulación Cerebrovascular/fisiología , Círculo Arterial Cerebral/fisiología , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Angiografía por Resonancia Magnética/métodos , Adulto , Velocidad del Flujo Sanguíneo/fisiología , Círculo Arterial Cerebral/anatomía & histología , Femenino , Humanos , Aumento de la Imagen/métodos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Background: Brain MRI in infants at ultra-high-field scanners might improve diagnostic quality, but safety should be evaluated first. In our previous study, we reported simulated specific absorption rates and acoustic noise data at 7 Tesla. Methods: In this study, we included twenty infants between term-equivalent age and three months of age. The infants were scanned on a 7 Tesla MRI directly after their clinically indicated 3 Tesla brain MRI scan. Vital parameters, temperature, and comfort were monitored throughout the process. Brain temperature was estimated during the MRI scans using proton MR spectroscopy. Results: We found no significant differences in vital parameters, temperature, and comfort during and after 7 Tesla MRI scans, compared to 3 Tesla MRI scans. Conclusions: These data confirm our hypothesis that scanning infants at 7 Tesla MRI appears to be safe and we identified no additional risks from scanning at 3 Tesla MRI.
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BACKGROUND: The aim of the study was to identify promoting and impeding factors for successful implementation of a Dutch primary health care-based lifestyle programme called 'BeweegKuur'. BeweegKuur aims to increase the physical activity and change the diet of people at increased health risk due to overweight or obesity. OBJECTIVE: To determine perceived promoting and impeding factors in the implementation of the BeweegKuur programme for overweight and obese people. METHODS: This study consisted of 3 focus group meetings with intervention participants, 15 interviews with health care professionals (HCPs) and 1 focus group session with dieticians. The interviews and focus groups were recorded and transcribed verbatim. The data were analysed with the Nvivo qualitative research software package. RESULTS: For some intervention participants, the invitation to participate in BeweegKuur came unexpectedly, as they had not been diagnosed with an illness. HCPs were aware of this and took time to explain to participants that the programme was appropriate and safe for them. Participants as well as professionals were generally positive about the feasibility of the programme for overweight and obese people. CONCLUSIONS: HCPs as well as intervention participants were motivated to participate in the programme, and generally indicated that the intervention was in accordance with their needs. The multidisciplinary approach and the combination of physical activity and dietary behaviour change can make the BeweegKuur programme a success if potential impeding factors like those identified in the present study are overcome.
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Conductas Relacionadas con la Salud , Promoción de la Salud/organización & administración , Estilo de Vida , Sobrepeso/terapia , Atención Primaria de Salud/organización & administración , Consejo , Grupos Focales , Humanos , Países Bajos , Obesidad/terapiaRESUMEN
Human noise can be harmful to sound-centric marine mammals. Significant research has focused on characterizing behavioral responses of protected cetacean species to navy mid-frequency active sonar (MFAS). Controlled exposure experiments (CEE) using animal-borne tags have proved valuable, but smaller dolphins are not amenable to tagging and groups of interacting individuals are more relevant behavioral units for these social species. To fill key data gaps on group responses of social delphinids that are exposed to navy MFAS in large numbers, we describe novel approaches for the coordinated collection and integrated analysis of multiple remotely-sensed datasets during CEEs. This involves real-time coordination of a sonar source, shore-based group tracking, aerial photogrammetry to measure fine-scale movements and passive acoustics to quantify vocal activity. Using an example CEE involving long-beaked common dolphins (Delphinus delphis bairdii), we demonstrate how resultant quantitative metrics can be used to estimate behavioral changes and noise exposure-response relationships.
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Delfín Común , Delfines , Acústica , Animales , Ruido , Tecnología de Sensores Remotos , SonidoRESUMEN
Fundamental insight on predator-prey dynamics in the deep sea is hampered by a lack of combined data on hunting behavior and prey spectra. Deep-sea niche segregation may evolve when predators target specific prey communities, but this hypothesis remains untested. We combined environmental DNA (eDNA) metabarcoding with biologging to assess cephalopod community composition in the deep-sea foraging habitat of two top predator cetaceans. Risso's dolphin and Cuvier's beaked whale selectively targeted distinct epi/meso- and bathypelagic foraging zones, holding eDNA of 39 cephalopod taxa, including 22 known prey. Contrary to expectation, extensive taxonomic overlap in prey spectra between foraging zones indicated that predator niche segregation was not driven by prey community composition alone. Instead, intraspecific prey spectrum differences may drive differentiation for hunting fewer, more calorific, mature cephalopods in deeper waters. The novel combination of methods presented here holds great promise to disclose elusive deep-sea predator-prey systems, aiding in their protection.
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Cefalópodos , ADN Ambiental , Animales , Cefalópodos/genética , Ecosistema , Conducta Predatoria , BallenasRESUMEN
BACKGROUND: We investigated antipsychotic drug prescription practice of Dutch ID physicians, studying prevalence of antipsychotic drug use, reasons for prescription and the relationship between these reasons and patient characteristics. METHODS: A cross-sectional study of medical and pharmaceutical records in a population living in residential settings of three care providers for persons with IDs in the Netherlands (n = 2373). RESULTS: Prevalence of antipsychotic drug use was 32.2% (95% CI 30.1-33.9). Behavioural problems were the reason for prescription of antipsychotic drugs in 58% of cases and psychotic disorder or psychotic symptoms in 22.5%. In 11.7% the diagnosis of psychotic disorder was specified according to DSM-IV criteria. In 18.5% the reason for prescription was not noted in the medical record. Behavioural problems as reason for prescription was associated with profound and severe ID, living in a central location and male sex. Psychotic disorder specified according to DSM-IV as indication for prescription was negatively associated with profound and severe ID and with presence of an additional mental disorder. Absence of a noted reason for prescription was associated with female sex and with the presence of an additional mental disorder. DISCUSSION: Current prevalence and reason for prescription of antipsychotic drugs are similar with outcomes of previous studies. Our results show the continuing lack of evidence-based psychopharmacological treatment in mental health care for persons with IDs.
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Antipsicóticos/uso terapéutico , Prescripciones de Medicamentos/estadística & datos numéricos , Discapacidad Intelectual/tratamiento farmacológico , Discapacidad Intelectual/epidemiología , Adulto , Anciano , Estudios Transversales , Medicina Basada en la Evidencia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , PrevalenciaRESUMEN
Visual hallucinations (VH) are common in patients with Parkinson's disease (PD), yet the underlying pathophysiological mechanisms are still unclear. We aimed to explore the association of the presence of VH with inner retinal thinning and, secondarily, with visual acuity. To this end, we included 40 PD patients in this exploratory study, of whom 14 had VH, and 22 age- and sex-matched healthy controls. All participants were interviewed for the presence of VH by a neurologist specialized in movement disorders and underwent a thorough ophthalmologic examination, including measurement of the best-corrected visual acuity (BCVA) and optical coherence tomography to obtain macular scans of the combined ganglion cell layer and inner plexiform layer (GCL-IPL). Patients with VH had a thinner GCL-IPL than patients without VH, which persisted after correction for age, disease stage, levodopa equivalent daily dose (LED) and cognitive function. Furthermore, BCVA was lower in the PD group with VH than in the PD group without VH, although only a trend remained after correction for age, disease stage, LED and cognitive function. Taken together, in patients with PD, visual hallucinations appear to be associated with a thinning of the inner retinal layers and, possibly, with reduced visual acuity. Further research using a longitudinal design is necessary to confirm these findings and to establish the causality of these relationships.
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Alucinaciones/complicaciones , Enfermedad de Parkinson/complicaciones , Retina/patología , Anciano , Cognición , Femenino , Alucinaciones/fisiopatología , Humanos , Modelos Logísticos , Masculino , Enfermedad de Parkinson/fisiopatología , Índice de Severidad de la Enfermedad , Agudeza VisualRESUMEN
BACKGROUND AND PURPOSE: Cerebral MR imaging in infants is usually performed with a field strength of up to 3T. In adults, a growing number of studies have shown added diagnostic value of 7T MR imaging. 7T MR imaging might be of additional value in infants with unexplained seizures, for example. The aim of this study was to investigate the feasibility of 7T MR imaging in infants. We provide information about the safety preparations and show the first MR images of infants at 7T. MATERIALS AND METHODS: Specific absorption rate levels during 7T were simulated in Sim4life using infant and adult models. A newly developed acoustic hood was used to guarantee hearing protection. Acoustic noise damping of this hood was measured and compared with the 3T Nordell hood and no hood. In this prospective pilot study, clinically stable infants, between term-equivalent age and the corrected age of 3 months, underwent 7T MR imaging immediately after their standard 3T MR imaging. The 7T scan protocols were developed and optimized while scanning this cohort. RESULTS: Global and peak specific absorption rate levels in the infant model in the centered position and 50-mm feet direction did not exceed the levels in the adult model. Hearing protection was guaranteed with the new hood. Twelve infants were scanned. No MR imaging-related adverse events occurred. It was feasible to obtain good-quality imaging at 7T for MRA, MRV, SWI, single-shot T2WI, and MR spectroscopy. T1WI had lower quality at 7T. CONCLUSIONS: 7T MR imaging is feasible in infants, and good-quality scans could be obtained.
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Recién Nacido , Lactante , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Proyectos Piloto , Estudios ProspectivosRESUMEN
OBJECTIVE: To show that eye movement abnormalities differ between essential tremor (ET) and tremor dominant Parkinson's disease (PD-T), and that these abnormalities reflect cerebellar dysfunction in ET and basal ganglia pathology in PD-T. METHODS: In this exploratory study, in 23 patients with ET, 21 age-matched patients with PD-T, and 19 age-matched healthy controls (HCs), we investigated visually guided saccades, antisaccades, and smooth pursuit eye movements (SPEM). RESULTS: While the ET group had a normal gain (saccade amplitude/target amplitude) and latency of saccades, the PD-T group had hypometric visually guided saccades, and a prolonged latency of visually guided saccades and antisaccades. The SPEM gain was similarly low in both ET and PD-T and was significantly lower in both patient groups than in the HC group. CONCLUSIONS: In ET, SPEM gain was reduced in the presence of normal saccades, whereas in PD-T, the reduced SPEM gain was accompanied by delayed saccade initiation and hypometric saccades, in line with cerebellar dysfunction in ET and basal ganglia dysfunction in PD-T. SIGNIFICANCE: These findings support the presumed cerebellar pathology in ET. In addition, the difference in saccade features may contribute to the groundwork for a quantitative diagnostic test to differentiate between these disorders.
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Ganglios Basales/fisiopatología , Cerebelo/fisiopatología , Temblor Esencial/diagnóstico , Movimientos Oculares/fisiología , Enfermedad de Parkinson/diagnóstico , Temblor/diagnóstico , Anciano , Diagnóstico Diferencial , Temblor Esencial/fisiopatología , Medidas del Movimiento Ocular , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/fisiopatología , Temblor/fisiopatologíaRESUMEN
The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.
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Tamaño Corporal , Cadena Alimentaria , Ballenas/anatomía & histología , Ballenas/fisiología , Animales , Evolución Biológica , Biomasa , Ingestión de Energía , Euphausiacea , Conducta Alimentaria , Océanos y MaresRESUMEN
Adipose-derived stem cells (ASCs) are promising candidates for therapy in myocardial infarction (MI). However, the frequency of human ASCs that differentiate towards cardiomyocytes is low. We hypothesized that adherence to extracellular matrix molecules that are upregulated after MI might increase human stem cell differentiation towards cardiomyocytes. We analysed putative ASC differentiation on fibronectin-coated, laminin-coated and uncoated culture plates. Expression of cardiac markers in cells was analysed 1, 3 and 5 weeks after stimulation with 5-aza-2-deoxycytidine. After 1 week, mRNA expression of myosin light chain-2alpha (MLC-2alpha), an early marker in cardiomyocyte development, was increased significantly in treated cells, independent of coating. At 5 weeks, however, mRNA expression of the late cardiomyocyte development marker SERCA2alpha was only significantly increased in 5-aza-2-deoxycytidine-treated cells cultured on laminin. Significantly higher numbers of cells were immunopositive for MLC-2alpha in cultures of treated cells grown on laminin-coated wells, when compared with cultures of treated cells grown on uncoated wells, both at 1 week and at 5 weeks. Furthermore, after 3 weeks, significantly more alpha-actinin- and desmin-positive cells were detected after treatment with 5-aza-2-deoxycytidine, but only in uncoated wells. After 5 weeks, however, the number of desmin-positive cells was only significantly increased after treatment of cells with 5-aza-2-deoxycytidine and culture on laminin (61% positive cells). Thus, we have found that a high percentage of human ASCs can be differentiated towards cardiomyocytes; this effect can be improved by laminin, especially during late differentiation.
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Tejido Adiposo/citología , Diferenciación Celular/efectos de los fármacos , Laminina/farmacología , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Células Madre/citología , Células Madre/efectos de los fármacos , Tejido Adiposo/metabolismo , Adulto , Azacitidina/farmacología , Biomarcadores/metabolismo , Recuento de Células , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Inmunohistoquímica , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Células Madre/metabolismoRESUMEN
BACKGROUND AND PURPOSE: Aneurysm volume pulsation is a potential predictor of intracranial aneurysm rupture. We evaluated whether 7T MR imaging can quantify aneurysm volume pulsation. MATERIALS AND METHODS: In Stage I of the study, 10 unruptured aneurysms in 9 patients were studied using a high-resolution (0.6-mm, isotropic) 3D gradient-echo sequence with cardiac gating. Semiautomatic segmentation was used to measure aneurysm volume (in cubic millimeters) per cardiac phase. Aneurysm pulsation was defined as the relative increase in volume between the phase with the smallest volume and the phase with the largest volume. The accuracy and precision of the measured volume pulsations were addressed by digital phantom simulations and a repeat image analysis. In Stage II, the imaging protocol was optimized and 9 patients with 9 aneurysms were studied with and without administration of a contrast agent. RESULTS: The mean aneurysm pulsation in Stage I was 8% ± 7% (range, 2%-27%), with a mean volume change of 15 ± 14 mm3 (range, 3-51 mm3). The mean difference in volume change for the repeat image analysis was 2 ± 6 mm3. The artifactual volume pulsations measured with the digital phantom simulations were of the same magnitude as the volume pulsations observed in the patient data, even after protocol optimization in Stage II. CONCLUSIONS: Volume pulsation quantification with the current imaging protocol on 7T MR imaging is not accurate due to multiple imaging artifacts. Future studies should always include aneurysm-specific accuracy analysis.
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Aneurisma Intracraneal/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodos , Adulto , Anciano , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad , Flujo PulsátilRESUMEN
OBJECTIVE: Advanced glycation end products (AGEs), such as N(epsilon)-(carboxymethyl)lysine (CML), are implicated in vascular disease. We previously reported increased CML accumulation in small intramyocardial blood vessels in diabetes patients. Diabetes patients have an increased risk for acute myocardial infarction (AMI). Here, we examined a putative relationship between CML and AMI. METHODS AND RESULTS: Heart tissue was stained for CML, myeloperoxidase, and E-selectin in AMI patients (n=26), myocarditis patients (n=17), and control patients (n=15). In AMI patients, CML depositions were 3-fold increased compared with controls in the small intramyocardial blood vessels and predominantly colocalized with activated endothelium (E-selectin-positive) both in infarction and noninfarction areas. A trend of increased CML positivity of the intima of epicardial coronary arteries did not reach significance in AMI patients. In the rat heart AMI model, CML depositions were undetectable after 24 hours of reperfusion, but became clearly visible after 5 days of reperfusion. In line with an inflammatory contribution, human myocarditis was also accompanied by accumulation of CML on the endothelium of intramyocardial blood vessels. CONCLUSIONS: CML, present predominantly on activated endothelium in small intramyocardial blood vessels in patients with AMI, might reflect an increased risk for AMI rather than being a result of AMI.
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Vasos Coronarios/metabolismo , Lisina/análogos & derivados , Infarto del Miocardio/metabolismo , Anciano , Animales , Selectina E/metabolismo , Células Endoteliales/metabolismo , Femenino , Humanos , Inmunohistoquímica , Lisina/biosíntesis , Lisina/metabolismo , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Reperfusión Miocárdica , Miocarditis/metabolismo , Estrés Oxidativo , Peroxidasa/metabolismo , Pronóstico , Ratas , Factores de Riesgo , Factores de TiempoRESUMEN
The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).