61 research outputs found
Prognostic value of myocardial perfusion scintigraphy in type 2 diabetic patients with mild, stable angina pectoris
Aim: To determine the prognostic value of reversible myocardial perfusion defects on myocardial perfusion scintigraphy (MPS) in patients with type 2 diabetes mellitus and mild anginal complaints. Methods and results: In the MERIDIAN trial, patients with diabetes mellitus type 2, stable, mild anginal symptoms (Canadian Cardiovascular Society classification (CCS) I-II/IV) and reversible perfusion defects were randomized to either continued pharmacological treatment or early invasive treatment. In this sub analysis, the severity of the myocardial perfusion defect was related to the occurrence of cardiac death and non-fatal myocardial infarction, in 319 patients (63% male, 65 ± 9 years). During follow-up (2.2 ± 0.6 years), 14 patients had a cardiac event: 3 in 171 patients without myocardial ischemia and 11 in 148 patients with myocardial ischemia. Annual event rates rose from 0.8% to 5.8% with increasing severity of myocardial ischemia. Multivariable analysis identified the presence of severe myocardial ischemia (hazard ratio (HR) 5.45, 95%CI 1.89-15.71) and insulin use (HR 4.00, 95%CI 1.25-12.75) as independent predictors of cardiac events. Conclusions: Type 2 diabetics with mild anginal symptoms with no or moderate myocardial ischemia have a low annual cardiac event rate. In patients with severe myocardial ischemia event rate increased 3-6 fold
1/f2 Characteristics and Isotropy in the Fourier Power Spectra of Visual Art, Cartoons, Comics, Mangas, and Different Categories of Photographs
Art images and natural scenes have in common that their radially averaged (1D) Fourier spectral power falls according to a power-law with increasing spatial frequency (1/f2 characteristics), which implies that the power spectra have scale-invariant properties. In the present study, we show that other categories of man-made images, cartoons and graphic novels (comics and mangas), have similar properties. Further on, we extend our investigations to 2D power spectra. In order to determine whether the Fourier power spectra of man-made images differed from those of other categories of images (photographs of natural scenes, objects, faces and plants and scientific illustrations), we analyzed their 2D power spectra by principal component analysis. Results indicated that the first fifteen principal components allowed a partial separation of the different image categories. The differences between the image categories were studied in more detail by analyzing whether the mean power and the slope of the power gradients from low to high spatial frequencies varied across orientations in the power spectra. Mean power was generally higher in cardinal orientations both in real-world photographs and artworks, with no systematic difference between the two types of images. However, the slope of the power gradients showed a lower degree of mean variability across spectral orientations (i.e., more isotropy) in art images, cartoons and graphic novels than in photographs of comparable subject matters. Taken together, these results indicate that art images, cartoons and graphic novels possess relatively uniform 1/f2 characteristics across all orientations. In conclusion, the man-made stimuli studied, which were presumably produced to evoke pleasant and/or enjoyable visual perception in human observers, form a subset of all images and share statistical properties in their Fourier power spectra. Whether these properties are necessary or sufficient to induce aesthetic perception remains to be investigated
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
A de novo nonsense mutation in MAGEL2 in a patient initially diagnosed as Opitz-C: similarities between Schaaf-Yang and Opitz-C syndromes
Opitz trigonocephaly C syndrome (OTCS) is a rare genetic disorder characterized by craniofacial anomalies, variable intellectual and psychomotor disability, and variable cardiac defects with a high mortality rate. Different patterns of inheritance and genetic heterogeneity are known in this syndrome. Whole exome and genome sequencing of a 19-year-old girl (P7), initially diagnosed with OTCS, revealed a de novo nonsense mutation, p.Q638*, in the MAGEL2 gene. MAGEL2 is an imprinted, maternally silenced, gene located at 15q11-13, within the Prader-Willi region. Patient P7 carried the mutation in the paternal chromosome. Recently, mutations in MAGEL2 have been described in Schaaf-Yang syndrome (SHFYNG) and in severe arthrogryposis. Patient P7 bears resemblances with SHFYNG cases but has other findings not described in this syndrome and common in OTCS. We sequenced MAGEL2 in nine additional OTCS patients and no mutations were found. This study provides the first clear molecular genetic basis for an OTCS case, indicates that there is overlap between OTCS and SHFYNG syndromes, and confirms that OTCS is genetically heterogeneous. Genes encoding MAGEL2 partners, either in the retrograde transport or in the ubiquitination-deubiquitination complexes, are promising candidates as OTCS disease-causing genes.Funding was from Associació Síndrome Opitz C, Terrassa, Spain; Spanish Ministerio de Economía y Competitividad (SAF2014-56562-R; FECYT, crowdfunding PRECIPITA); Catalan Government (2014SGR932) and from CIBERER (U720). We acknowledge support of the Spanish Ministry of Economy and Competitiveness, 'Centro de Excelencia Severo Ochoa 2013-2017'
Temporo-spatial distribution of blood vessels in human lumbar intervertebral discs
While there is consensus in the literature that blood vessels are confined to the outer anulus fibrosus of normal adult intervertebral disc, debate continues whether there is a vascular in-growths into inner parts of the intervertebral disc during degeneration. We therefore tested the hypothesis that vascular in-growth is not a distinct feature of disc degeneration. The specific endothelial cell marker CD 31 (PECAM) was used to immunohistochemically investigate 42 paraffin-embedded complete mid-sagittal human intervertebral disc sections of various ages (0–86 years) and varying extent of histomorphological degeneration. Additionally, 20 surgical disc samples from individuals (26–69 years) were included in this study. In discs of fetal to infantile age, blood vessels perforated the cartilaginous end plate and extended into the inner and outer anulus fibrosus, but not into the nucleus pulposus. In adolescents and adults, no blood vessels were seen except for the outer zone of the anulus fibrosus adjacent to the insertion to ligaments. The cartilaginous end plate remained free of vessels, except for areas with circumscribed destruction of the end plate. In advanced disc degeneration, no vessels were observed except for those few cases with complete, scar-like disc destruction. However, some rim lesions and occasionally major clefts were surrounded by a small network of capillary blood vessels extending into deeper zones of the anulus fibrosus. A subsequent morphometric analysis, revealed slightly “deeper” blood vessel extension in juvenile/adolescent discs when compared to young, mature and senile adult individuals with significantly “deeper” extension in the posterior than anterior anulus. The analysis of the surgical specimens showed that only sparse capillary blood vessels which did not extend into the nucleus pulposus even in major disc disruption. Our results show that vascular invasion deeper than the periphery was not observed during disc degeneration, which supports the hypothesis that vascular in-growth is not a distinct feature of disc degeneration
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