3,519 research outputs found
Orthostatic intolerance and autonomic dysfunction following bariatric surgery: A retrospective study and review of the literature
The prevalence and costs of the obesity epidemic and obesity-related conditions, including diabetes mellitus, is consistently increasing worldwide. Bariatric medicine is attempting to address this with weight loss and exercise programmes, and with increasing frequency, various forms of bariatric surgery. There has been considerable success reported after bariatric surgery but not without. We describe 14 patients with orthostatic intolerance (OI) post bariatric surgery. We report on OI (postural dizziness, palpitations and fainting), the results of cardiovascular autonomic testing and the associated and/or causative findings as well as reviewing the literature to consider the possible mechanisms.
Comprehensive autonomic testing revealed that 35.7% (Buchwald et al., 2004) of these patients fulfilled the criteria for the Postural Tachycardia Syndrome (PoTS), 57.1% (Cremieux et al., 2008) had low levels of basal BP and 42.9% (Cammisotto & Bendayan, 2007) patients were presyncopal and 14.3% (Billakanty et al., 2008) experienced syncope. We propose that the incidence of OI post-bariatric surgery is higher than considered, that certain cohorts may be more susceptible to complications, and that further research is needed to identify the prevalence and, ideally anticipate occurrence. With the increasing prevalence of obesity and required clinical interventions, further understanding of the pathophysiological processes causing autonomic dysfunction after bariatric interventions will aid management, which may differ in those with an underlying disposition to autonomic involvement, such as diabetics, in whom such procedures are increasingly used
Orthostatic intolerance and autonomic dysfunction following bariatric surgery: A retrospective study and review of the literature
The prevalence and costs of the obesity epidemic and obesity-related conditions, including diabetes mellitus, is consistently increasing worldwide. Bariatric medicine is attempting to address this with weight loss and exercise programmes, and with increasing frequency, various forms of bariatric surgery. There has been considerable success reported after bariatric surgery but not without. We describe 14 patients with orthostatic intolerance (OI) post bariatric surgery. We report on OI (postural dizziness, palpitations and fainting), the results of cardiovascular autonomic testing and the associated and/or causative findings as well as reviewing the literature to consider the possible mechanisms.
Comprehensive autonomic testing revealed that 35.7% (Buchwald et al., 2004) of these patients fulfilled the criteria for the Postural Tachycardia Syndrome (PoTS), 57.1% (Cremieux et al., 2008) had low levels of basal BP and 42.9% (Cammisotto & Bendayan, 2007) patients were presyncopal and 14.3% (Billakanty et al., 2008) experienced syncope. We propose that the incidence of OI post-bariatric surgery is higher than considered, that certain cohorts may be more susceptible to complications, and that further research is needed to identify the prevalence and, ideally anticipate occurrence. With the increasing prevalence of obesity and required clinical interventions, further understanding of the pathophysiological processes causing autonomic dysfunction after bariatric interventions will aid management, which may differ in those with an underlying disposition to autonomic involvement, such as diabetics, in whom such procedures are increasingly used
Phenotypic effects of expanded ataxin-1 polyglutamines with interruptions in vitro
Spinocerebellar ataxia type 1 is a neurodegenerative disease caused by expansion of an uninterrupted glutamine repeat in ataxin-1 protein. Protein aggregation and immunoreactivity to 1C2 monoclonal antibody are two distinct pathognomonic features of expanded ataxin-1, as well as of other polyglutamine disorders. Rare cases of non-affected elderly subjects carrying expanded ataxin-1 alleles were found in random population. However, in these alleles the glutamine stretch was interrupted by histidines. Due to lack of phenotype, these alleles should be considered "normal". Most importantly, occurrence of these unusual alleles provides a unique opportunity to investigate which molecular properties of expanded ataxin-1 are not coupled to polyglutamine pathogenesis. Towards this goal, we compared in vitro the immunoreactivity to 1C2 antibody and the ability to form aggregates of interrupted and uninterrupted alleles. Immunoblotting showed that expanded-interrupted ataxin-1 had an affinity to 1C2 resembling that of normal ataxin-1. On the contrary, filter assay showed that aggregation rate of expanded-interrupted ataxin-1 resembles that of expanded-uninterrupted ataxin-1. These observations indicate that affinity for 1C2 does not directly correlate with self-aggregation of ataxin-1. Moreover, self-aggregation is not directly affected by histidine interruptions. In conclusion, these results support the hypothesis that mechanisms underlying neuronal degeneration are triggered by protein misfolding rather than by protein aggregation
AM 1934-563: A giant spiral polar-ring galaxy in a triplet
We have observed the emission-line kinematics and photometry of a southern
triplet of galaxies. The triplet contains a giant spiral galaxy AM 1934-563
which optical structure resembles a polar-ring galaxy: distorted spiral disk,
seen almost edge-on, and a faint large-scale (45 kpc in diameter) warped
structure, inclined by 60^o-70^o with respect to the disk major axis. The
triplet shows relatively small velocity dispersion (69 km/s) and a large
crossing time (0.17 in units of the Hubble time). The disk of AM 1934-563
demonstrates optical colors typical for an early-type spirals, strong radial
color gradient, and almost exponential surface brightness distribution with an
exponential scale-length value of 3.1 kpc (R passband). The galaxy shows a
maximum rotation velocity of about 200 km/s and it lies close to the
Tully-Fisher relation for spiral galaxies. The suspected polar ring is faint
(\mu(B) > 24) and strongly warped. Its total luminosity comprises (10-15)% of
the total luminosity of AM 1934-563. We then try to model this system using
numerical simulations, and study its possible formation mechanisms. We find
that the most robust model, that reproduces the observed characteristics of the
ring and the host galaxy, is the tidal transfer of mass from a massive gas-rich
donor galaxy to the polar ring. The physical properties of the triplet of
galaxies are in agreement with this scenario.Comment: Accepted for publication in A&
New photometric investigation of the double ringed galaxy ESO474-G26. Unveiling the formation scenario
We present a detailed photometric study of the peculiar double ringed galaxy
ESO474-G26. Near-Infrared (NIR) and optical data have been used, with the main
goal to constrain the formation history of ESO474-G26. NIR photometry is
fundamental in this kind of study, because gives better constraints on the
Spectral Energy Distribution (SED) and well traces the older stellar population
of the galaxy. This galaxy presents a very complex structure, with two almost
orthogonal rings, one in the equatorial and another in the polar plane, around
an elliptical-like object. Due to the peculiar morphology of ESO474-G26, we
used both NIR images (J and K bands) to derive accurate analysis of the stellar
light distribution, and optical images (in the B, V and R bands) to derive
color profiles and color maps to study the structure of the rings. The
observational characteristic of ESO474-G26 are typical of galaxies which have
experienced some kind of interactions during their evolution. We investigated
two alternatives: a merging process and an accretion event.Comment: 19 pages, 20 figures. Accepted for publication in Monthly Notices of
the Royal Astronomical Society (MNRAS
Lower urinary tract dysfunction in Parkinsonian syndromes
Purpose of review: The aim of this review is to outline the clinical presentation, pathophysiology and evaluation of lower urinary tract (LUT) dysfunction in Parkinson’s disease and other parkinsonian syndromes including multiple system atrophy, dementia with Lewy bodies, progressive supranuclear palsy and corticobasal degeneration. // Recent findings: LUT dysfunction commonly occurs in neurological disorders, including patients with parkinsonian syndromes. The pattern of LUT dysfunction and its severity are variable, depending upon the site of lesion within the neural pathways. Parkinsonian syndromes are broadly divided into Parkinson’s disease (PD) and a typical parkinsonian syndromes such as multiple system atrophy (MSA), dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Different parkinsonian syndromes have distinct clinical features (e.g. dysautonomia, early dementia, supranuclear gaze palsy, higher cortical signs), and the pattern of LUT dysfunction and its severity can differ. // Conclusions: LUT dysfunction is a common feature in patients with parkinsonian syndromes. Recognising the pattern of LUT dysfunction during the assessment of these patients can help management and possibly facilitate an earlier diagnosis
VEGAS: a VST Early-type GAlaxy Survey. IV. NGC 1533, IC 2038 and IC 2039: an interacting triplet in the Dorado group
This paper focuses on NGC 1533 and the pair IC 2038 and IC 2039 in Dorado a
nearby, clumpy, still un-virialized group. We obtained their surface photometry
from deep OmegaCAM@ESO-VST images in g and r bands. For NGC 1533, we map the
surface brightness down to mag/arcsec and mag/arcsec and out to about . At such faint levels
the structure of NGC 1533 appear amazingly disturbed with clear structural
asymmetry between inner and outer isophotes in the North-East direction. We
detect new spiral arm-like tails in the outskirts, which might likely be the
signature of a past interaction/merging event. Similarly, IC 2038 and IC 2039
show tails and distortions indicative of their ongoing interaction. Taking
advantages of deep images, we are able to detect the optical counterpart to the
HI gas. The analysis of the new deep data suggests that NGC 1533 had a complex
history made of several interactions with low-mass satellites that generated
the star-forming spiral-like structure in the inner regions and are shaping the
stellar envelope. In addition, the VST observations show that also the two less
luminous galaxies, IC 2038 and IC 2039, are probably interacting each-other
and, in the past, IC 2038 could have also interacted with NGC 1533, which
stripped away gas and stars from its outskirts. The new picture emerging from
this study is of an interacting triplet, where the brightest galaxy NGC 1533
has ongoing mass assembly in the outskirts.Comment: Accepted for publication in The Astronomical Journal. High-resolution
version of paper is available at the following link:
https://www.dropbox.com/preview/VEGAS_IV.pdf?role=persona
24 hour-ambulatory blood pressure and heart rate profiles in diagnosing orthostatic hypotension in Parkinson’s disease and Multiple System Atrophy
Background:24-hour ambulatory blood pressure and heart rate monitoring (24hr-ABPM) can provide vital information on circadian blood pressure (BP) profiles, which are commonly abnormal in Parkinson’s disease with and without autonomic failure (PD+AF and PD) and multiple system atrophy (MSA). 24hr-ABPM has not been directly compared between these disorders regarding cardiovascular autonomic function. We aim to determine the usefulness of 24hr-ABPM with diary compared to Head-up Tilting (HUT) in diagnosing orthostatic hypotension (OH) in these patients.
Methods: 74 patients (23 MSA,18 PD+AF,33 PD) underwent cardiovascular autonomic screening followed by 24hr-ABPM with diary. Standing tests were included during 24hr-ABPM. The sensitivity and specificity in detecting OH from the 24hr-ABPM standing test were compared with HUT.
Results: There was no difference in OH during HUT between MSA and PD+AF (p>0.05). MSA and PD+AF had a higher proportion of abnormal BP circadian rhythms compared to PD (p0.05). Patients were divided into groups with (OH+) and without OH (OH-) on HUT. Using the standing test during 24hr-ABPM, a SBP fall of >20 mmHg showed a sensitivity and specificity of 82% and 100 % (AUC 0.91, 95% CI 0.84-0.98) in differentiating OH+ from OH-, respectively.
Conclusions:PD+AF and MSA patients had similar circadian BP patterns suggesting that autonomic dysfunction influences abnormal BP circadian patterns similarly in these disorders. The higher sensitivity and specificity in detecting OH using a SBP fall of >20 mmHg compared to a DBP fall of >10 mmHg during standing test supports its usefulness to assess autonomic function in MSA and PD
Polar Ring Galaxies and the Tully Fisher relation: implications for the dark halo shape
We have investigated the Tully-Fisher relation for Polar Ring Galaxies
(PRGs), based on near infrared, optical and HI data available for a sample of
these peculiar objects. The total K-band luminosity, which mainly comes from
the central host galaxy, and the measured HI linewidth at 20% of the peak line
flux density, which traces the potential in the polar plane, place most polar
rings of the sample far from the Tully-Fisher relation defined for spiral
galaxies, with many PRGs showing larger HI linewidths than expected for the
observed K band luminosity. This result is confirmed by a larger sample of
objects, based on B-band data. This observational evidence may be related to
the dark halo shape and orientation in these systems, which we study by
numerical modeling of PRG formation and dynamics: the larger rotation
velocities observed in PRGs can be explained by a flattened polar halo, aligned
with the polar ring.Comment: 22 pages, 8 postscript figures, accepted for publication in
Astrophysical Journa
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