585 research outputs found
Regional serum cholesterol differences in Belgium: do genetically determined cardiovascular risk factors contribute?
BACKGROUND: Differences in serum lipid distribution and mortality from
ischaemic heart disease have repeatedly been reported between Belgian
northerners and southerners. We investigated whether serum lipoprotein(a)
(Lp(a)) and apolipoprotein (apo) E polymorphism were involved. METHODS:
Fasting serum lipids, apo A-I and B, and Lp(a) levels were examined in
randomly selected, 20-39 year old Belgian males and females from the north
(Flanders) and the south (Wallonia) of Belgium (N = 900). Apo E phenotype
distribution was investigated in random subsamples from either region (N =
249). RESULTS: Mean serum cholesterol, low density lipoprotein cholesterol
(LDL-c), apo B and triglyceride levels were higher in Walloons compared to
Flemings within each gender, the difference being significant in 30-39
year old males. Average high density lipoprotein cholesterol and apo A-I
levels were significantly lower in 30-39 year old male southerners,
compared to their northern counterparts. Median Lp(a) was 67 mg/l in
northerners and 75 mg/l in southerners (NS). The apo E phenotype
distribution was similar in both regions (chi2 = 7.213; d.f. = 5; P =
0.2053), whereas the average effects of the apo E alleles differed between
the regions. In southerners the epsilon4 effect upon adjusted apo B and
LDL-c levels was approximately+12% and the epsilon2 effect was
approximately-15%; in northerners the epsilon4 and epsilon2 effects were
approximately+5% and approximately-25%, respectively. The apo E
polymorphism did not affect serum Lp(a) levels. CONCLUSIONS: Regional
cholesterol differences between Flemings and Walloons cannot be explained
by differences in serum Lp(a) or apo E phenotype distribution. The less
favourable epsilon2 and epsilon4 effects in southerners compared to
northerners reflect modulation of the apo E gene by particular
environments
Laboratoriumgeneeskunde: van evolutie naar revolutie
Oratie uitgesproken door Prof.dr. C.M. Cobbaert bij de aanvaarding van het ambt van hoogleraar in de Klinische Chemie en Laboratoriumgeneeskunde aan de Universiteit Leiden op vrijdag 19 februari 2016Oratie uitgesproken door Prof.dr. C.M. Cobbaert bij de aanvaarding van het ambt van hoogleraar in de Klinische Chemie en Laboratoriumgeneeskunde aan de Universiteit Leiden op vrijdag 19 februari 2016
Back Pain Secondary to Brucella Spondylitis in the Lumbar Region
Brucellosis is a systemic, infectious disease caused by the bacterial genus Brucella and a common zoonosis that still remains a major health problem in certain parts of the world such as the Mediterranean region, the Middle East, and Latin America. It may involve multiple organs and tissues. Osteoarticular involvement is the most frequent complication of brucellosis, in which the diagnosis of brucellar spondylitis is often difficult since the clinical presentation may be obscured by many other conditions. There are only a few reports on brucellar spondylitis in Korea. Here, we report a case of spondylitis due to brucella in an elderly male
Identifying Conifer Tree vs. Deciduous Shrub and Tree Regeneration Trajectories in a Space-for-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar
Wildland fires and anthropogenic disturbances can cause changes in vegetation species composition and structure in boreal peatlands. These could potentially alter regeneration trajectories following severe fire or through cumulative impacts of climate-mediated drying, fire, and/or anthropogenic disturbance. We used lidar-derived point cloud metrics, and site-specific locational attributes to assess trajectories of post-disturbance vegetation regeneration in boreal peatlands south of Fort McMurray, Alberta, Canada using a space-for-time-chronosequence. The objectives were to (a) develop methods to identify conifer trees vs. deciduous shrubs and trees using multi-spectral lidar data, (b) quantify the proportional coverage of shrubs and trees to determine environmental conditions driving shrub regeneration, and (c) determine the spatial variations in shrub and tree heights as an indicator of cumulative growth since the fire. The results show that the use of lidar-derived structural metrics predicted areas of deciduous shrub establishment (92% accuracy) and classification of deciduous and conifer trees (71% accuracy). Burned bogs and fens were more prone to shrub regeneration up to and including 38 years after the fire. The transition from deciduous to conifer trees occurred approximately 30 years post-fire. These results improve the understanding of environmental conditions that are sensitive to disturbance and impacts of disturbance on northern peatlands within a changing climate
Une approche génétique pour la dérivation de règles et méta-règles de transformation de modèles à partir d'exemples
Quantifying apolipoprotein(a) in the era of proteoforms and precision medicine
Lipoprotein(a) (Lp(a)) is an independent risk factor in the development of atherosclerotic cardiovascular diseases (ASCVD) and calcific aortic valve disease (CAVD). Lp(a) is an LDL-like particle to which apolipoprotein (a) (apo(a)) is covalently bound. Apo(a) contains a variable number of kringle IV repeats, a kringle V and a protease domain. Serum/plasma Lp(a) concentrations are traditionally expressed as total particle mass in mg/L. Concern has arisen lately as flawed Lp(a) mass tests have masked its clinical utility.The determinants of variability in Lp(a) composition were investigated, including the apo(a) size polymorphism, post-translational modifications -N- and O-glycosylation- and the lipid:protein ratio. Depending on the number of kringle IV-2 repeats, the theoretical protein content of the Lp(a) particle varies between 30 and 46 (w/w) %, which inescapably confounds Lp(a) mass measurements.The authors advocate that reporting of Lp(a) particle concentrations in mass units is metrologically inappropriate and should be abandoned, as it results in systematically biased Lp(a) results. Enabling technology, such as mass spectrometry, allows unequivocal molecular characterization of the apo(a) measurand(s) and accurate quantitation of apo(a) in molar units, unaffected by apo(a) size polymorphism. To guarantee that Lp(a)/apo(a) tests are fit-for-clinical-purpose, basic metrology principles should be implemented upfront during test development.Afdeling Klinische Chemie en Laboratoriumgeneeskunde (AKCL
Significance of various parameters derived from biological variability of lipoprotein(a), homocysteine, cysteine, and total antioxidant status
Analytical and biological components of variability and various derived
indices have been determined for lipoprotein(a) [Lp(a)], homocysteine
(Hcy), cysteine (Cys), and total antioxidant status (TAOS) in ostensibly
healthy adult Caucasians and in stable outpatients with an increased serum
Lp(a). In healthy Caucasians, average intraindividual biological CVs (CVb)
were 20.0% for Lp(a), 9.4% for Hcy, 5.9% for Cys, and 2.8% for TAOS, CVbs
being similar in men and women. In the outpatient group, CVbs were
comparable for Hcy, Cys, and TAOS, but significantly lower for Lp(a) (7.5%
vs 20.0%; P <0.0001). Moreover, a significant inverse relation between
both biological and analytical CVs (CVa) and serum Lp(a) concentrations
was demonstrated. We conclude that average CVa and CVb values, and hence
average derived indices, are adequate for Hcy, Cys, and TAOS, whereas
individual values should be used for Lp(a)
Modulation of Lipoprotein(a) Atherogenicity by High Density Lipoprotein Cholesterol Levels in Middle-Aged Men With Symptomatic Coronary Artery Disease and Normal to Moderately Elevated Serum Cholesterol
Survey of total error of precipitation and homogeneous HDL-cholesterol methods and simultaneous evaluation of lyophilized saccharose-containing candidate reference materials for HDL-cholesterol
BACKGROUND: Standardization of HDL-cholesterol is needed for risk
assessment. We assessed for the first time the accuracy of HDL-cholesterol
testing in The Netherlands and evaluated 11 candidate reference materials
(CRMs). METHODS: The total error (TE) of HDL-cholesterol measurements was
assessed in native human sera by 25 Dutch clinical chemistry laboratories.
Concomitantly, the suitability of lyophilized, saccharose-containing CRMs
(n = 11) for HDL-cholesterol was evaluated. RESULTS: In the precipitation
method group, which included 25 laboratories and four methods, the mean
(minimum-maximum) TE was 11.5% (2.7-25.2%), signifying that 18 of 25
laboratories satisfied the TE goal of </=13% issued by the National
Cholesterol Education Program (NCEP). In the homogeneous HDL-cholesterol
method group, which included five laboratories, each performing two
different methods, the mean (minimum-maximum) TE was 9.5% (6.0-17.3%) for
the Boehringer assay and 15.7% (3.3-30.7%) for the Genzyme assay. For the
Boehringer homogeneous assay, one of five laboratories did not meet the TE
criterion, whereas for the Genzyme homogeneous assay, three of five
laboratories exceeded the 13% criterion. The biases on the HDL-cholesterol
values found by various precipitation methods were highly variable in all
CRMs, irrespective of the quality, whereas the biases found by the
homogeneous method from Boehringer were far less than +/-5% for the
highest-quality CRMs (CRMs 4-6). CONCLUSIONS: The NCEP goal was met by 24
of 35 laboratories assessed by use of native human sera. Selectively
pooled, lyophilized CRMs that are cryoprotected with 200 g/L saccharose
have ample potential for use in the standardization of homogeneous
HDL-cholesterol methods
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