327 research outputs found
Plasma osteopontin concentrations in preeclampsia - is there an association with endothelial injury?
Background: It has been previously reported that plasma
osteopontin (OPN) concentrations are increased in cardiovascular
disorders. The goal of the present study was to determine plasma
OPN concentrations in healthy pregnant women and preeclamptic
patients, and to investigate their relationship to the clinical
characteristics of the study subjects and to markers of
inflammation [C-reactive protein (CRP)], endothelial activation
[von Willebrand factor antigen (VWF: Ag)] or endothelial injury
(fibronectin), oxidative stress [malondialdehyde (MDA)] and
trophoblast debris (cell-free fetal DNA). Methods: Forty-four
patients with preeclampsia and 44 healthy pregnant women matched
for age and gestational age were involved in this case-control
study. Plasma OPN concentrations were measured with ELISA. Serum
CRP concentrations were determined with an autoanalyzer using
the manufacturer's reagents. Plasma VWF: Ag was quantified by
ELISA, while plasma fibronectin concentrations were measured by
nephelometry. Plasma MDA concentrations were estimated by the
thiobarbituric acid-based colorimetric assay. The amount of
cell-free fetal DNA in maternal plasma was determined by
quantitative real-time PCR analysis of the sex-determining
region Y (SRY) gene. For statistical analyses, non-parametric
methods were applied. Results: Serum levels of CRP, as well as
plasma concentrations of VWF: Ag, fibronectin, MDA and cell-free
fetal DNA were significantly higher in preeclamptic patients
than in healthy pregnant women. There was no significant
difference in plasma OPN concentrations between controls and the
preeclamptic group. However, preeclamptic patients with plasma
fibronectin concentrations in the upper quartile had
significantly higher plasma OPN concentrations than those below
the 75th percentile, as well as healthy pregnant women [median
(interquartile range): 9.38 (8.10-11.99) vs. 7.54 (6.31-9.40)
and 7.40 (6.51-8.80) ng/mL, respectively, p < 0.05 for both].
Furthermore, in preeclamptic patients, plasma OPN concentrations
showed a significant positive linear association with plasma
fibronectin (Spearman R = 0.38, standardized regression
coefficient (beta) = 0.41, p < 0.05 for both). Conclusions:
Plasma OPN concentrations are increased in preeclamptic patients
with extensive endothelial injury. However, further studies are
warranted to explore the relationship between OPN and
endothelial damage. Clin Chem Lab Med 2010;48: 181-7
Factors influencing quality of life following lower limb amputation for peripheral arterial occlusive disease: a systematic review of the literature
Background: The majority of lower limb amputations are undertaken in people with peripheral arterial occlusive disease,\ud
and approximately 50% have diabetes. Quality of life is an important outcome in lower limb amputations; little is known\ud
about what influences it, and therefore how to improve it.\ud
Objectives: The aim of this systematic review was to identify the factors that influence quality of life after lower limb\ud
amputation for peripheral arterial occlusive disease.\ud
Methods: MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science and Cochrane databases were searched to identify\ud
articles that quantitatively measured quality of life in those with a lower limb amputation for peripheral arterial occlusive\ud
disease. Articles were quality assessed by two assessors, evidence tables summarised each article and a narrative\ud
synthesis was performed.\ud
Study design: Systematic review.\ud
Results: Twelve articles were included. Study designs and outcome measures used varied. Quality assessment scores\ud
ranged from 36% to 92%. The ability to walk successfully with a prosthesis had the greatest positive impact on quality\ud
of life. A trans-femoral amputation was negatively associated with quality of life due to increased difficulty in walking\ud
with a prosthesis. Other factors such as older age, being male, longer time since amputation, level of social support and\ud
presence of diabetes also negatively affected quality of life.\ud
Conclusion: Being able to walk with a prosthesis is of primary importance to improve quality of life for people with lower\ud
limb amputation due to peripheral arterial occlusive disease. To further understand and improve the quality of life of this\ud
population, there is a need for more prospective longitudinal studies, with a standardised outcome measure
Pathological Investigation of Congenital Bicuspid Aortic Valve Stenosis, Compared with Atherosclerotic Tricuspid Aortic Valve Stenosis and Congenital Bicuspid Aortic Valve Regurgitation
Congenital bicuspid aortic valve (CBAV) is the main cause of aortic stenosis (AS) in young adults. However, the histopathological features of AS in patients with CBAV have not been fully investigated.We examined specimens of aortic valve leaflets obtained from patients who had undergone aortic valve re/placement at our institution for severe AS with CBAV (n = 24, CBAV-AS group), severe AS with tricuspid aortic valve (n = 24, TAV-AS group), and severe aortic regurgitation (AR) with CBAV (n = 24, CBAV-AR group). We compared the histopathological features among the three groups. Pathological features were classified using semi-quantitative methods (graded on a scale 0 to 3) by experienced pathologists without knowledge of the patients' backgrounds. The severity of inflammation, neovascularization, and calcium and cholesterol deposition did not differ between the CBAV-AS and TAV-AS groups, and these four parameters were less marked in the CBAV-AR group than in the CBAV-AS (all p<0.01). Meanwhile, the grade of valvular fibrosis was greater in the CBAV-AS group, compared with the TAV-AS and CBAV-AR groups (both p<0.01). In AS patients, thickness of fibrotic lesions was greater on the aortic side than on the ventricular side (both p<0.01). Meanwhile, thickness of fibrotic lesions was comparable between the aortic and ventricular sides in CBAV-AR patients (p = 0.35).Valvular fibrosis, especially on the aortic side, was greater in patients with CBAV-AS than in those without, suggesting a difference in the pathogenesis of AS between CBAV and TAV
Opening a new window to other worlds with spectropolarimetry
A high level of diversity has already been observed among the planets of our
own Solar System. As such, one expects extrasolar planets to present a wide
range of distinctive features, therefore the characterisation of Earth- and
super Earth-like planets is becoming of key importance in scientific research.
The SEARCH (Spectropolarimetric Exoplanet AtmospheRe CHaracerisation) mission
proposal of this paper represents one possible approach to realising these
objectives. The mission goals of SEARCH include the detailed characterisation
of a wide variety of exoplanets, ranging from terrestrial planets to gas
giants. More specifically, SEARCH will determine atmospheric properties such as
cloud coverage, surface pressure and atmospheric composition, and may also be
capable of identifying basic surface features. To resolve a planet with a semi
major axis of down to 1.4AU and 30pc distant SEARCH will have a mirror system
consisting of two segments, with elliptical rim, cut out of a parabolic mirror.
This will yield an effective diameter of 9 meters along one axis. A phase mask
coronagraph along with an integral spectrograph will be used to overcome the
contrast ratio of star to planet light. Such a mission would provide invaluable
data on the diversity present in extrasolar planetary systems and much more
could be learned from the similarities and differences compared to our own
Solar System. This would allow our theories of planetary formation, atmospheric
accretion and evolution to be tested, and our understanding of regions such as
the outer limit of the Habitable Zone to be further improved.Comment: 23 pages, accepted for publication in Experimental Astronom
Alcohol policy enforcement and changes in student drinking rates in a statewide public college system: a follow-up study
<p>Abstract</p> <p>Background</p> <p>Heavy alcohol use among U.S. college students is a major contributor to young adult morbidity and mortality. The aim of this study was to examine whether college alcohol policy enforcement levels predict changes in student drinking and related behaviors in a state system of public colleges and universities, following a system-wide change to a stricter policy.</p> <p>Methods</p> <p>Students and administrators at 11 Massachusetts public colleges/universities completed surveys in 1999 (N of students = 1252), one year after the policy change, and again in 2001 (N = 1074). We calculated policy enforcement scores for each school based on the reports of deans of students, campus security chiefs, and students, and examined the correlations between perceived enforcement levels and the change in student drinking rates over the subsequent two year period, after weighting the 2001 data to adjust for demographic changes in the student body.</p> <p>Results</p> <p>Overall rates of any past-30-days drinking, heavy episodic drinking, and usual heavy drinking among past-30-days drinkers were all lower in 2001 compared to 1999. School-level analyses (N = 11) found deans' baseline reports of stricter enforcement were strongly correlated with subsequent declines in heavy episodic drinking (Pearson's r = -0.73, p = 0.011). Moreover, consistently high enforcement levels across time, as reported by deans, were associated with greater declines in heavy episodic drinking. Such relationships were not found for students' and security chiefs' reports of enforcement. Marijuana use did not rise during this period of decline in heavy drinking.</p> <p>Conclusions</p> <p>Study findings suggest that stronger enforcement of a stricter alcohol policy may be associated with reductions in student heavy drinking rates over time. An aggressive enforcement stance by deans may be an important element of an effective college alcohol policy.</p
ACE inhibition attenuates uremia-induced aortic valve thickening in a novel mouse model
<p>Abstract</p> <p>Background</p> <p>We examined whether impaired renal function causes thickening of the aortic valve leaflets in hyperlipidemic apoE-knockout (apoE<sup>-/-</sup>) mice, and whether the putative effect on the aortic valves could be prevented by inhibiting the angiotensin-converting enzyme (ACE) with enalapril.</p> <p>Methods</p> <p>Thickening of the aortic valve leaflets in apoE<sup>-/- </sup>mice was induced by producing mild or moderate chronic renal failure resulting from unilateral nephrectomy (1/2 NX, n = 18) or subtotal nephrectomy (5/6 NX, n = 22), respectively. Additionally, the 5/6 NX mice were randomized to no treatment (n = 8) or enalapril treatment (n = 13). The maximal thickness of each leaflet was measured from histological sections of the aortic roots.</p> <p>Results</p> <p>Leaflet thickness was significantly greater in the 5/6 NX mice than in the 1/2 NX mice (P = 0.030) or the unoperated mice (P = 0.003). The 5/6 NX mice treated with enalapril had significantly thinner leaflets than did the untreated 5/6 NX mice (P = 0.014).</p> <p>Conclusion</p> <p>Moderate uremia causes thickening of the aortic valves in apoE<sup>-/- </sup>mice, which can be attenuated by ACE inhibition. The nephrectomized apoE<sup>-/- </sup>mouse constitutes a new model for investigating the mechanisms of uremia-induced aortic valve disease, and also provides an opportunity to study its pharmacologic prevention.</p
A new efficient trial design for assessing reliability of ankle-brachial index measures by three different observer groups
BACKGROUND: The usual method of assessing the variability of a measure such as the ankle brachial index (ABI) as a function of different observer groups is to obtain repeated measurements. Because the number of possible observer-subject combinations is impractically large, only a few small studies on inter- and intraobserver variability of ABI measures have been carried out to date. The present study proposes a new and efficient study design. This paper describes the study methodology. METHODS: Using a partially balanced incomplete block design, six angiologists, six primary-care physicians and six trained medical office assistants performed two ABI measurements each on six individuals from a group of 36 unselected subjects aged 65–70 years. Each test subject is measured by one observer from each of the three observer groups, and each observer measures exactly six of the 36 subjects in the group. Each possible combination of two observers occurs exactly once per patient and is not repeated on a second subject. The study involved four groups of 36 subjects (144), plus standbys. RESULTS: The 192 volunteers present at the study day were similar in terms of demographic characteristics and vascular risk factors: mean age 68.6 ± 1.7; mean BMI 29.1 ± 4.6; mean waist-hip ratio 0.92 ± 0.09; active smokers 12%; hypertension 60.9%; hypercholesterolemia 53.4%; diabetic 17.2%. A complete set of ABI measurements (three observers performing two Doppler measurements each) was obtained from 108 subjects. From all other subjects at least one ABI measurement was obtained. The mean ABI was 1.08 (± 0.13), 15 (7.9%) volunteers had an ABI <0.9, and none had an ABI >1.4, i.e. a ratio that may be associated with increased stiffening of the arterial walls. CONCLUSION: This is the first large-scale study investigating the components of variability and thus reliability in ABI measurements. The advantage of the new study design introduced here is that only one sixth of the number of theoretically possible measurements is required to obtain information about measurement errors. Bland-Altman plots show that there are only small differences and no systematic bias between the observers from three occupational groups with different training backgrounds
Relationship between cardiovascular risk factors and biomarkers with necrotic core and atheroma size: a serial intravascular ultrasound radiofrequency data analysis
We explored the impact of patient demographics, anthropometric measurements, cardiovascular risk factors, and soluble biomarkers on necrotic core and atheroma size in patients with coronary disease. The IBIS-2 trial enrolled 330 patients. In the multivariate analysis, at baseline, creatinine had a positive, whereas baseline mean lumen diameter and myeloperoxidase had a negative, independent association with percentage of necrotic core (PNC); while age, glomerular filtration rate <60, HbA1c, previous PCI or CABG and baseline % diameter stenosis were positively, and acute coronary syndromes (ACS) were negatively associated with baseline percentage atheroma volume (PAV). The variables associated with a decrease in PNC from baseline were darapladib, ACS and a large content of NC at baseline, while variables associated with an increase in PNC were previous stroke and % diameter stenosis at baseline. Those variables associated with a decrease in PAV from baseline were waist circumference, statin use, CD40L and baseline PAV, while the only variable associated with an increase in PAV was baseline diastolic blood pressure. Treatment with darapladib was associated with a decrease in necrotic core, but was not associated with a decrease in percentage atheroma volume. On the contrary, statin use was only associated with a decrease in percentage atheroma volume
Is there a role of statins in the prevention of aortic biological prostheses degeneration
It has been recently observed that statins might slow the progression of aortic stenosis or sclerosis. Preliminary reports suggested a similar positive effect in reducing the degeneration of aortic valve bioprostheses even though this hypothesis should be further proven and supported by new data. In this review the present evidences of the possible effects of statins in this field are discussed
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