57 research outputs found
Migraine and vascular disease biomarkers: A population-based case-control study.
Background The underpinnings of the migraine-stroke association remain uncertain, but endothelial activation is a potential mechanism. We evaluated the association of migraine and vascular disease biomarkers in a community-based population. Methods Participants (300 women, 117 men) were recruited as a part of the Dutch CAMERA 1 (Cerebral Abnormalities in Migraine, an Epidemiologic Risk Analysis) study. Participants were aged 30-60 (mean 48) years, 155 migraine had with aura (MA), 128 migraine without aura (MO), and 134 were controls with no severe headaches. Plasma concentrations of fibrinogen, Factor II, D-dimer, high sensitivity C-reactive protein (hs-CRP), and von Willebrand factor antigen were compared between groups, also stratifying by sex. Results Fibrinogen and hs-CRP were elevated in migraineurs compared to controls. In logistic regression analyses, MO and MA had increased likelihood of elevated fibrinogen, and MA had increased likelihood of elevated Factor II and hs-CRP. Fibrinogen and Factor II were associated with MA in women but not men. In the migraine subgroup, the total number of years of aura, but not headache, predicted elevated hs-CRP, and the average number of aura, but not headache, attacks predicted all biomarkers but Factor II. Conclusions Elevated vascular biomarkers were associated with migraine, particularly MA, as well as with years of aura and number of aura attacks
Large-Scale Gravitational Instability and Star Formation in the Large Magellanic Cloud
Large-scale star formation in disk galaxies is hypothesized to be driven by
global gravitational instability. The observed gas surface density is commonly
used to compute the strength of gravitational instability, but according to
this criterion star formation often appears to occur in gravitationally stable
regions. One possible reason is that the stellar contribution to the
instability has been neglected. We have examined the gravitational instability
of the Large Magellanic Cloud (LMC) considering the gas alone, and considering
the combination of collisional gas and collisionless stars. We compare the
gravitationally unstable regions with the on-going star formation revealed by
Spitzer observations of young stellar objects. Although only 62% of the massive
young stellar object candidates are in regions where the gas alone is unstable,
some 85% lie in regions unstable due to the combination of gas and stars. The
combined stability analysis better describes where star formation occurs. In
agreement with other observations and numerical models, a small fraction of the
star formation occurs in regions with gravitational stability parameter Q > 1.
We further measure the dependence of the star formation timescale on the
strength of gravitational instability, and quantitatively compare it to the
exponential dependence expected from numerical simulations.Comment: Accepted for publication in ApJ, 10 pages, 5 figure
Star Formation in Isolated Disk Galaxies. II. Schmidt Laws and Efficiency of Gravitational Collapse
(Abridged). We model gravitational instability in a wide range of isolated
disk galaxies, using GADGET, a three-dimensional, smoothed particle
hydrodynamics code. The model galaxies include a dark matter halo and a disk of
stars and isothermal gas. The global Schmidt law observed in disk galaxies is
quantitatively reproduced by our models. We find that the surface density of
star formation rate directly correlates with the strength of local
gravitational instability. The local Schmidt laws of individual galaxies in our
models show clear evidence of star formation thresholds. Our results suggest
that the non-linear development of gravitational instability determines the
local and global Schmidt laws, and the star formation thresholds.Comment: 21 pages, 15 figures, to appear on ApJ March 2006. (Paper I is ApJ
626, 823, 2005, or astro-ph/0501022
Cortical glutamate and gamma-aminobutyric acid over the course of a provoked migraine attack, a 7 Tesla magnetic resonance spectroscopy study
Enhanced activity of the glutamatergic system has been linked to migraine pathophysiology. The present study aimed to assess the involvement of the glutamatergic system in the onset of attacks. We provoked attacks by infusion of glyceryl trinitrate (GTN; 0.5 ”g/kg/min over 20 min) in 24 female episodic migraineurs without aura and 13 female age-matched healthy controls. Over the course of a single day participants were scanned three times at fixed time slots (baseline before GTN infusion, 90 min and 270 min after start of GTN infusion). Single-volume proton magnetic resonance spectra (1HâMRS) were acquired at 7 Tesla from a volume of interest (VOI, 2x2x3 cm) in the visual cortex. We assessed the concentrations of glutamate, its major precursor glutamine, and its product gamma-aminobutyric acid (GABA) over the course of a provoked attack. The preictal state was defined as the period after GTN infusion until the migraine-like headache started, independent of possible experienced premonitory symptoms, and the ictal state was defined as the period with provoked migraine-like headache. Data were analyzed using a linear mixed-effect model for repeated measures. Glutamate and glutamine levels did not change from interictal to the preictal and ictal state. GABA levels increased from interictal towards the preictal state for migraine patients compared with healthy controls. We conclude that high resolution 7T MRS is able to show changes in the glutamatergic system towards a triggered migraine attack, by revealing an increased GABA concentration associated with the onset of a migraine attack
A Search for Extended Ultraviolet Disk (XUV-disk) Galaxies in the Local Universe
We have initiated a search for extended ultraviolet disk (XUV-disk) galaxies
in the local universe. Herein, we compare GALEX UV and visible--NIR images of
189 nearby (D40 Mpc) S0--Sm galaxies included in the GALEX Atlas of Nearby
Galaxies and present the first catalogue of XUV-disk galaxies. We find that
XUV-disk galaxies are surprisingly common but have varied relative (UV/optical)
extent and morphology. Type~1 objects (\ga20% incidence) have structured,
UV-bright/optically-faint emission features in the outer disk, beyond the
traditional star formation threshold. Type~2 XUV-disk galaxies (10%
incidence) exhibit an exceptionally large,
UV-bright/optically-low-surface-brightness (LSB) zone having blue
outside the effective extent of the inner, older stellar population, but not
reaching extreme galactocentric distance. If the activity occuring in XUV-disks
is episodic, a higher fraction of present-day spirals could be influenced by
such outer disk star formation. Type~1 disks are associated with spirals of all
types, whereas Type~2 XUV-disks are predominantly found in late-type spirals.
Type~2 XUV-disks are forming stars quickly enough to double their [presently
low] stellar mass in the next Gyr (assuming a constant SF rate). XUV-disk
galaxies of both types are systematically more gas-rich than the general galaxy
population. Minor external perturbation may stimulate XUV-disk incidence, at
least for Type~1 objects. XUV-disks are the most actively evolving galaxies
growing via inside-out disk formation in the current epoch, and may constitute
a segment of the galaxy population experiencing significant, continued gas
accretion from the intergalactic medium or neighboring objects.Comment: 83 pages, 16 figures, 2 tables. Appearing in the GALEX special issue
of ApJS. (A version with high quality figures and proof corrections can be
found at http://www.journals.uchicago.edu/toc/apjs/173/2
The cardiovascular risk profile of middle-aged women with polycystic ovary syndrome
Contains fulltext :
220851.pdf (Publisherâs version ) (Open Access)OBJECTIVES: Contradictory results have been reported regarding the association between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD). We assessed the cardiometabolic phenotype and prevalence of CVD in middle-aged women with PCOS, compared with age-matched controls from the general population, and estimated 10-year CVD risk and cardiovascular health score. DESIGN: A cross-sectional study. PARTICIPANTS: 200 women aged >45 with PCOS, and 200 age-matched controls. MEASUREMENTS: Anthropometrics, insulin, lipid levels, prevalence of metabolic syndrome and type II diabetes. Ten-year Framingham risk score and the cardiovascular health score were calculated, and carotid intima-media thickness (cIMT) was measured. RESULTS: Mean age was 50.5 years (SD = 5.5) in women with PCOS and 51.0 years (SD = 5.2) in controls. Increased waist circumference, body mass index and hypertension were more often observed in women with PCOS (P < .001). In women with PCOS, the prevalence of type II diabetes and metabolic syndrome was not significantly increased and lipid levels were not different from controls. cIMT was lower in women with PCOS (P < .001). Calculated cardiovascular health and 10-year CVD risk were similar in women with PCOS and controls. CONCLUSIONS: Middle-aged women with PCOS exhibit only a moderately unfavourable cardiometabolic profile compared to age-matched controls, even though they present with an increased BMI and waist circumference. Furthermore, we found no evidence for increased (10-year) CVD risk or more severe atherosclerosis compared with controls from the general population. Long-term follow-up of women with PCOS is necessary to provide a definitive answer concerning long-term risk for CVD
The cardiovascular risk profile of middle-aged women with polycystic ovary syndrome
Objectives: Contradictory results have been reported regarding the association between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD). We assessed the cardiometabolic phenotype and prevalence of CVD in middle-aged women with PCOS, compared with age-matched controls from the general population, and estimated 10-year CVD risk and cardiovascular health score. Design: A cross-sectional study. Participants: 200 women aged >45 with PCOS, and 200 age-matched controls. Measurements: Anthropometrics, insulin, lipid levels, prevalence of metabolic syndrome and type II diabetes. Ten-year Framingham risk score and the cardiovascular health score were calculated, and carotid intima-media thickness (cIMT) was measured. Results: Mean age was 50.5Â years (SDÂ =Â 5.5) in women with PCOS and 51.0Â years (SDÂ =Â 5.2) in controls. Increased waist circumference, body mass index and hypertension were more often observed in women with PCOS (PÂ <.001). In women with PCOS, the prevalence of type II diabetes and metabolic syndrome was not significantly increased and lipid levels were not different from controls. cIMT was lower in women with PCOS (PÂ <.001). Calculated cardiovascular health and 10-year CVD risk were similar in women with PCOS and controls. Conclusions: Middle-aged women with PCOS exhibit only a moderately unfavourable cardiometabolic profile compared to age-matched controls, even though they present with an increased BMI and waist circumference. Furthermore, we found no evidence for increased (10-year) CVD risk or more severe atherosclerosis compared with controls from the general population. Long-term follow-up of women with PCOS is necessary to provide a definitive answer concerning lon
Brain stem and cerebellar hyperintense lesions in migraine.
BACKGROUND AND PURPOSE: Migraineurs are at increased risk of cerebellar infarcts and supratentorial white matter lesions. The prevalence, frequency, and distribution of infratentorial hyperintense lesions in migraine are unknown. METHODS: Migraineurs with aura (n=161), without aura (n=134), and controls (n=140) from a population-based sample of adults (30 to 60 years of age) were evaluated with MRI. RESULTS: Infratentorial hyperintensities were identified in 13 of 295 (4.4%) migraineurs and in 1 of 140 (0.7%) controls (P=0.04). Twelve cases had hyperintensities, mostly bilaterally, in the dorsal basis pontis. Those with infratentorial hyperintensities also had supratentorial white matter lesions more often. CONCLUSIONS: We found an increased prevalence of infratentorial (mostly pontine) hyperintensities in migraineurs from the general population. This extends the knowledge about vulnerable brain regions and type of lesions in migraine brains. A hemodynamic ischemic pathogenesis is likely, but further research is needed
Brain atrophy following hemiplegic migraine attacks
Background Patients with hemiplegic migraine (HM) may sometimes develop progressive neurological deterioration of which the pathophysiology is unknown. Patient We report a 16-year clinical and neuroradiological follow-up of a patient carrying a de novo p.Ser218Leu CACNA1A HM mutation who had nine severe HM attacks associated with seizures and decreased consciousness between the ages of 3 and 12 years. Results Repeated ictal and postictal neuroimaging revealed cytotoxic oedema during severe HM attacks in the symptomatic hemisphere, which later showed atrophic changes. In addition, progressive cerebellar atrophy was observed. Brain atrophy halted after cessation of severe attacks, possibly due to prophylactic treatment with flunarizine and sodium valproate. Conclusion Severe HM attacks may result in brain atrophy and prophylactic treatment of these attacks might be needed in an early stage of disease to prevent permanent brain damag
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