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Erscheinungsjahr
- 2012 (61) (entfernen)
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- Wissenschaftlicher Artikel (38)
- Konferenzveröffentlichung (15)
- Dissertation (6)
- Rezension (2)
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- ja (61)
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- vitamin A (3)
- Diabetic nephropathy (2)
- Linagliptin (2)
- obesity (2)
- plasma (2)
- retinol (2)
- (2E)-Hexadecenal (1)
- 25-OH vitamin D (1)
- 3,4-didehydroretinol (1)
- ACE inhibitors (1)
Institut
- Institut für Ernährungswissenschaft (61) (entfernen)
Background: Given the huge impact of vitamin D deficiency on a broad spectrum of diseases such as rickets, osteoporosis, mineral bone disease-vascular calcification syndrome, infectious diseases, but also several types of cancer and CNS diseases, reliable and simple methods to analyze the vitamin D status are urgently needed.
Methods: We developed an easy technique to determine the 25-OH vitamin D status from dried blood samples on filter paper. This allows determination of the 25-OH vitamin D status independently of venous blood taking, since only sampling of capillary blood is required for this new method. We compared the results of vitamin D measurements from venous blood of 96 healthy blood donors with those from capillary blood taken from the same patients at the same time. The capillary blood was dried on filter paper using the D-Vital ID dry-blood collection system.
Results: 25-OH vitamin D concentration data from extracted dried capillary blood filters correlated very well with data obtained after direct measurement of venous blood samples of the same blood donor (R: 0.7936; p<0.0001). The correlation was linear over the whole range of 25-OH vitamin D concentrations seen in this study. A Bland-Altman plot revealed good agreement between both tests.
Conclusions: The D-Vital ID dry-blood collection system showed an excellent performance as compared to the classical way of 25-OH vitamin D measurement from venous blood. This new technique will facilitate easy and reliable measurement for vitamin D status, in particular, in rural or isolated areas, developing countries, and field studies.
Background. Despite considerable progress made in the past decade through salt iodization programs, over 2 billion people worldwide still have inadequate iodine intake, with devastating consequences for brain development and intellectual capacity. To optimize these programs with regard to salt iodine content, careful monitoring of salt iodine content is essential, but few methods are available to quantitatively measure iodine concentration in a simple, fast, and safe way.
Objective. We have validated a newly developed device that quantitatively measures the content of potassium iodate in salt in a simple, safe, and rapid way.
Methods. The linearity, determination and detection limit, and inter- and intra-assay variability of this colorimetric method were assessed and the method was compared with iodometric titration, using salt samples from several countries.
Results. Linearity of analysis ranged from 5 to 75 mg/kg iodine, with I mg/kg being the determination limit; the intra- and interassay imprecision was 0.9%, 0.5%, and 0.7% and 1.5%, 1.7%, and 2.5% for salt samples with iodine contents of 17, 30, and 55 mg/kg, respectively; the interoperator imprecision for the same samples was 1.2%, 4.9%, and 4.7%, respectively. Comparison with the iodometric method showed high agreement between the methods (R-2 = 0.978; limits of agreement, -10.5 to 10.0 mg/kg).
Conclusions. The device offers a field- and user-friendly solution to quantifying potassium iodate salt content reliably. For countries that use potassium iodide in salt iodization programs, further validation is required.
Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC).
Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma.
Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene).
Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L.
Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed.
Ultrasound evaluation of the patellar tendon cross-sectional area and its relation to maximum force
(2012)
OBJECTIVE-BMI and albumin are commonly accepted parameters to recognize wasting in dialysis patients and are powerful predictors of morbidity and mortality. However, both parameters reveal limitations and may not cover the entire range of patients with wasting. The visceral protein transthyretin (TTR) may be helpful in overcoming the diagnostic and prognostic gap. Therefore, the aim of this study was to assess the association of TTR with morbidity and mortality in hemodialysis patients.
RESEARCH DESIGN AND METHODS-The TTR concentration was determined in plasma samples of 1,177 hemodialysis patients with type 2 diabetes. Cox regression analyses were used to determine hazard ratios (HRs) for the risk of cardiovascular end points (CVEs) and mortality according to quartiles of TTR concentration for the total study cohort and the subgroups BMI >= 23 kg/m(2), albumin concentration >= 3.8 g/dL, and a combination of both.
RESULTS-A low TTR concentration was associated with an increased risk for CVE for the total study cohort (HR 1.65 [95% CI 1.27-2.14]), patients with BMI >= 23 kg/m(2) (1.70 [1.22-2.37]), albumin >= 3.8 g/dL (1.68 [1.17-2.42]), and the combination of both (1.69 [1.13-2.53]). Additionally, a low TTR concentration predicted mortality for the total study cohort (1.79 [1.43-2.24]) and patients with BMI >= 23 kg/m(2) (1.46 [1.09-1.95]).
CONCLUSIONS-The current study demonstrated that TTR is a useful predictor for cardiovascular outcome and mortality in diabetic hemodialysis patients. TTR was particularly useful in patients who were not identified to be at risk by BMI or albumin status.
Test-retest-reliability of metabolic and cardiovascular load during isokinetic strength testing
(2012)
The majority of cases of community-acquired pneumonia are caused by Streptococcus pneumoniae and most studies on pneumococcal host interaction are based on cell culture or animal experiments. Thus, little is known about infections in human lung tissue.
Cyclooxygenase-2 and its metabolites play an important regulatory role in lung inflammation. Therefore, we established a pneumococcal infection model on human lung tissue demonstrating mitogen-activated protein kinase (MAPK)-dependent induction of cyclooxygenase-2 and its related metabolites.
In addition to alveolar macrophages and the vascular endothelium, cyclooxygenase-2 was upregulated in alveolar type II but not type I epithelial cells, which was confirmed in lungs of patients suffering from acute pneumonia. Moreover, we demonstrated the expression profile of all four E prostanoid receptors at the mRNA level and showed functionality of the E prostanoid(4) receptor by cyclic adenosine monophosphate production. Additionally, in comparison to previous studies, cyclooxygenase-2/prostaglandin E-2 related pro- and anti-inflammatory mediator regulation was partly confirmed in human lung tissue after pneumococcal infection.
Overall, cell type-specific and MAPK-dependent cyclooxygenase-2 expression and prostaglandin E-2 formation in human lung tissue may play an important role in the early phase of pneumococcal infections.