As current kidney replacement therapies are not efficient enough for end-stage renal disease (ESRD) treatment, a bioartificial kidney (BAK) device, based on conditionally immortalized human proximal tubule epithelial cells (ciPTEC), could represent an attractive solution. The active transport activity of such a system was recently demonstrated. In addition, endocrine functions of the cells, such as vitamin D activation, are relevant. The organic anion transporter 1 (OAT-1) overexpressing ciPTEC line presented 1α-hydroxylase (CYP27B1), 24-hydroxylase (CYP24A1) and vitamin D receptor (VDR), responsible for vitamin D activation, degradation and function, respectively. The ability to produce and secrete 1α,25-dihydroxy-vitamin D3, was shown after incubation with the precursor, 25-hydroxy-vitamin D3. The beneficial effect of vitamin D on cell function and behavior in uremic conditions was studied in the presence of an anionic uremic toxins mixture. Vitamin D could restore cell viability, and inflammatory and oxidative status, as shown by cell metabolic activity, interleukin-6 (IL-6) levels and reactive oxygen species (ROS) production, respectively. Finally, vitamin D restored transepithelial barrier function, as evidenced by decreased inulin-FITC leakage in biofunctionalized hollow fiber membranes (HFM) carrying ciPTEC-OAT1. In conclusion, the protective effects of vitamin D in uremic conditions and proven ciPTEC-OAT1 endocrine function encourage the use of these cells for BAK application.
Article Utility of dilution tests in investigating interference in the free thyroxine assay was published on January 1, 2017 in the journal Clinical Chemistry and Laboratory Medicine (CCLM) (volume 55, issue 1).
To study the composition of intracavitary deposits on Essure® hysteroscopic sterilization devices. Case report. Reproductive Medicine and Gynecology department of a University Hospital. A 39 years old patient presenting with a request for surgical removal of Essure® sterilization devices. Diagnostic hysteroscopy showed a crystal like white deposit attached to one of the devices. Diagnostic hysteroscopy and surgical removal of Essure® devices was performed. The deposits were collected and infrared spectroscopy analysis was performed. Chemical composition of the deposits attached to the device. Infrared spectroscopy of the material showed patterns conclusive with calcite (calcium carbonate, CaCO3). Until now, it is not clear if there is a relationship between reported complaints and formation of calcite deposits on Essure®. Infrared spectroscopy of deposits on Essure® devices showed a pattern conclusive with calcite. The relationship between reported complaints and the formation of calcite deposits on Essure® remains unclear.
Objective: Insulin‐like growth factor 1 (IGF‐1) measurements play a central role in the diagnosis and follow‐up of acromegaly and growth hormone deficiency. However, improving health care outcomes for these patients involves an intricate process of laboratory diagnostics and skilled health care professionals. The integrated effects of IGF‐1 reports on diagnosis and treatment decisions are yet unknown.Design, Patients and Measurements: Extended quality assessment, distributing the description of five (real) patient cases with accompanying blood samples. Patients suspected or during follow up for acromegaly or adult onset of growth hormone deficiency were included. Laboratory specialists and endocrinologists in the same centre were asked to interpret their centre‐specific IGF‐1 results by using a laboratory and medical questionnaire. This way, insight could be obtained into the combined effects of different assays, assay harmonisation, reference value sets, and individual physician interpretation in relation to guidelines, thus reviewing the entire diagnostic and management process.Results: Limited variation (CV 13.8 ± 2.8) was found in IGF‐1 concentrations despite different use of the harmonization sample and factor among laboratories. This interlaboratory variation increased upon conversion to SD scores (CV 15.7 ± 40.7) as a consequence of the use of different reference value sets. Furthermore, there was a lack of adherence to international guidelines among endocrinologists.Conclusions: Highly variable diagnostic and treatment outcomes in acromegaly and AGHD in the Netherlands can be attributed to increased variability of IGF‐1 upon conversion to SD scores and low adherence to clinical guidelines.