189 research outputs found
742-4 Radial Artery Graft: Angiographic Follow-up
Interest in the use of the radial artery (RA) as a coronary bypass graft has increased. Attention to harvesting and use of perioperative calcium channel inhibitors have ameliorated problems with spasm noted in earlier studies. Since 1993, 72 patients (pts) underwent grafting using a free RA from the non-dominant forearm. Re-angiography was performed in 24 pts to date and is the subject of this study. Pts ranged from 39–79 years (mean 55.5); all had 2 or 3 vessel disease and an average of 3 grafts/pt were constructed (range 2–4). Left internal thoracic artery (L1TA) was used in all cases except 1. The RA was a single graft in 19 including 2 to the LAD system, 12 to the circumflex system and 5 to the RCA. The RA-was sequential in 5 cases. Of the 24 pts catheterized an average of 9 weeks post-op 24/24 RA's were patent: 1 (sequential) RA had a mid-graft stenosis. There was no spasm seen in any RA. RA distal diameters (2.6mm) were well matched to the recipient vessel (RV) (2.2mm). The ratio RV/graft diameter was 0.83 for the radial artery similar to the ratio for the L1TA (0.90).ConclusionThe RA is a viable coronary conduit, easily harvested and has excellent early patency rates
A general theorem on angular-momentum changes due to potential vorticity mixing and on potential-energy changes due to buoyancy mixing
An initial zonally symmetric quasigeostrophic potential-vorticity (PV)
distribution q_i(y) is subjected to complete or partial mixing within some
finite zone |y| < L, where y is latitude. The change in M, the total absolute
angular momentum, between the initial and any later time is considered. For
standard quasigeostrophic shallow-water beta-channel dynamics it is proved
that, for any q_i(y) such that dq_i/dy > 0 throughout |y| < L, the change in M
is always negative. This theorem holds even when "mixing" is understood in the
most general possible sense. Arbitrary stirring or advective rearrangement is
included, combined to an arbitrary extent with spatially inhomogeneous
diffusion. The theorem holds whether or not the PV distribution is zonally
symmetric at the later time. The same theorem governs Boussinesq
potential-energy changes due to buoyancy mixing in the vertical. For the
standard quasigeostrophic beta-channel dynamics to be valid the Rossby
deformation length L_D >> \epsilon L where \epsilon is the Rossby number; when
L_D = \infty the theorem applies not only to the beta-channel, but also to a
single barotropic layer on the full sphere, as considered in the recent work of
Dunkerton and Scott on "PV staircases". It follows that the M-conserving PV
reconfigurations studied by those authors must involve processes describable as
PV unmixing, or anti-diffusion, in the sense of time-reversed diffusion.
Ordinary jet self-sharpening and jet-core acceleration do not, by contrast,
require unmixing, as is shown here by detailed analysis. Mixing in the jet
flanks suffices. The theorem extends to multiple layers and continuous
stratification. A corollary is a new nonlinear stability theorem for shear
flows.Comment: 14 pages, 4 figures; Final version, accepted by J. Atmos. Sci, in
pres
Linear dynamics of weakly viscous accretion disks: A disk analog of Tollmien-Schlichting waves
This paper discusses new perspectives and approaches to the problem of disk
dynamics where, in this study, we focus on the effects of viscous instabilities
influenced by boundary effects. The Boussinesq approximation of the viscous
large shearing box equations is analyzed in which the azimuthal length scale of
the disturbance is much larger than the radial and vertical scales. We examine
the stability of a non-axisymmetric potential vorticity mode, i.e. a
PV-anomaly. in a configuration in which buoyant convection and the
strato-rotational instability do not to operate. We consider a series of
boundary conditions which show the PV-anomaly to be unstable both on a finite
and semi-infinite radial domains. We find these conditions leading to an
instability which is the disk analog of Tollmien-Schlichting waves. When the
viscosity is weak, evidence of the instability is most pronounced by the
emergence of a vortex sheet at the critical layer located away from the
boundary where the instability is generated. For some boundary conditions a
necessary criterion for the onset of instability for vertical wavelengths that
are a sizable fraction of the layer's thickness and when the viscosity is small
is that the appropriate Froude number of the flow be greater than one. This
instability persists if more realistic boundary conditions are applied,
although the criterion on the Froude number is more complicated. The unstable
waves studied here share qualitative features to the instability seen in
rotating Blasius boundary layers. The implications of these results are
discussed. An overall new strategy for exploring and interpreting disk
instability mechanisms is also suggested.Comment: Accepted for publication in Astronomy and Astrophysics. 18 pages.
This version 3 with corrected style fil
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Genome-wide association study identifies 30 loci associated with bipolar disorder.
Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P < 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P < 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder
Randomized trials fit for the 21st century. A joint opinion from the European Society of Cardiology, American Heart Association, American College of Cardiology, and the World Heart Federation
© The Author(s) 2022. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. When citing this article, a citation from any of the journals listed is appropriate. For commercial re-use, please contact [email protected] controlled trials are the cornerstone for reliably evaluating therapeutic strategies. However, during the past 25 years, the rules and regulations governing randomized trials and their interpretation have become increasingly burdensome, and the cost and complexity of trials has become prohibitive. The present model is unsustainable, and the development of potentially effective treatments is often stopped prematurely on financial grounds, while existing drug treatments or non-drug interventions (such as screening strategies or management tools) may not be assessed reliably. The current ‘best regulatory practice’ environment, and a lack of consensus on what that requires, too often makes it unduly difficult to undertake efficient randomized trials able to provide reliable evidence about the safety and efficacy of potentially valuable interventions. Inclusion of underrepresented population groups and lack of diversity also remain among the
challenges.info:eu-repo/semantics/publishedVersio
Brain serotonin depletion enhances the sodium appetite induced by sodium depletion or beta-adrenergic stimulation
The impact of childhood abuse and recent stress on serum brain-derived neurotrophic factor and the moderating role of BDNF Val66Met
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98431.pdf (publisher's version ) (Open Access)RATIONALE: Recent findings show lowered brain-derived neurotrophic factor (BDNF) levels in major depressive disorder (MDD). Exposure to stressful life events may (partly) underlie these BDNF reductions, but little is known about the effects of early or recent life stress on BDNF levels. Moreover, the effects of stressful events on BDNF levels may in part be conditional upon a common variant on the BDNF gene (Val(66)Met; RS6265), with the Met allele being associated with a decrease in activity-dependent secretion of BDNF compared to the Val allele. METHODS: We investigated cross-sectionally in 1,435 individuals with lifetime MDD the impact of childhood abuse (CA) and recent life events on serum BDNF levels and assessed whether the impact of these events was moderated by the BDNF Val(66)Met polymorphism. RESULTS: Overall, BDNF Met carriers had reduced serum BDNF levels when exposed to CA in a dose-dependent way. Moreover, exposure to recent life events was also associated with decreases in BDNF levels, but this was independent of BDNF Val(66)Met. Moreover, when not exposed to CA, Met carriers had higher BDNF levels than the Val/Val individuals, who did not show decreases in BDNF associated with CA. Finally, these findings were only apparent in the MDD group without comorbid anxiety. CONCLUSIONS: These gene-environment interactions on serum BDNF levels suggest that Met carriers are particularly sensitive to (early) stressful life events, which extends previous findings on the moderating role of the BDNF Val(66)Met polymorphism in the face of stressful life events
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The resolution sensitivity of the South Asian monsoon and Indo-Pacific in a global 0.35◦ AGCM
The South Asian monsoon is one of the most significant manifestations of the seasonal cycle. It directly impacts nearly one third of the world’s population and also has substantial global influence. Using 27-year integrations of a high-resolution atmospheric general circulation model (Met Office Unified Model), we study changes in South Asian monsoon precipitation and circulation when horizontal resolution is increased from approximately 200 to 40 km at the equator (N96 to N512, 1.9 to 0.35◦). The high resolution, integration length and ensemble size of the dataset make this the most extensive dataset used to evaluate the resolution sensitivity of the South Asian monsoon to date. We find a consistent pattern of JJAS precipitation and circulation changes as resolution increases, which include a slight increase in precipitation over peninsular India, changes in Indian and Indochinese orographic rain bands, increasing wind speeds in the Somali Jet, increasing precipitation over the Maritime Continent islands and decreasing precipitation over the northern Maritime Continent seas. To diagnose which resolution related processes cause these changes we compare them to published sensitivity experiments that change regional orography and coastlines. Our analysis indicates that improved resolution of the East African Highlands results in the improved representation of the Somali Jet and further suggests that improved resolution of orography over Indochina and the Maritime Continent results in more precipitation over the Maritime Continent islands at the expense of reduced precipitation further north. We also evaluate the resolution sensitivity of monsoon depressions and lows, which contribute more precipitation over northeast India at higher resolution. We conclude that while increasing resolution at these scales does not solve the many monsoon biases that exist in GCMs, it has a number of small, beneficial impacts
Cyclic Vomiting Syndrome in 41 adults: the illness, the patients, and problems of management
BACKGROUND: Cyclic Vomiting Syndrome (CVS) is a disorder characterized by recurrent, stereotypic episodes of incapacitating nausea, vomiting and other symptoms, separated by intervals of comparative wellness. This report describes the clinical features, co-morbidities and problems encountered in management of 41 adult patients who met the diagnostic criteria for CVS. METHODS: This is a retrospective study of adults with CVS seen between 1994 and 2003. Follow-up data were obtained by mailed questionnaires. RESULTS: Age of onset ranged from 2 to 49 years. The duration of CVS at the time of consultation ranged from less than 1 year to 49 years. CVS episodes were stereotypic in respect of their hours of onset, symptomatology and length. Ninety-three percent of patients had recognizable prodromes. Half of the patients experienced a constellation of symptoms consisting of CVS episodes, migraine diathesis, inter-episodic dyspeptic nausea and a history of panic attacks. Deterioration in the course of CVS is indicated by coalescence of episodes in time. The prognosis of CVS is favorable in the majority of patients. CONCLUSION: CVS is a disabling disorder affecting adults as well as children. Because its occurrence in adults is little known, patients experience delayed or mis-diagnosis and ineffectual, sometimes inappropriately invasive management
Primary prevention of secondary disorders: A proposal and agenda
This paper calls for consideration of a new class of preventive interventions designed explicitly to prevent comorbidity of psychiatric disorders. Epidemiologic data show that successful interventions of this type could be extremely valuable, as up to half of lifetime psychiatric disorders and an even larger percent of chronic and seriously impairing disorders occur to people with a prior history of some other disorder. Furthermore, a review of etiologic hypotheses concerning the causes of comorbidity suggests that interventions aimed at primary prevention of secondary disorders might be feasible. However, more basic risk factor research is needed on the causes of comorbidity before we can make a clear assessment of feasibility and discover promising intervention targets. A number of methodological problems arise in carrying out this type of formative research. These problems are reviewed and suggestions are offered for solutions involving innovations in measurement, design, and data analysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44044/1/10464_2004_Article_BF00942174.pd
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