TY  - JOUR
A1  - Devine, Eric
A1  - Krieter, Detlef H.
A1  - Rüth, Marieke
A1  - Jankovski, Joachim
A1  - Lemke, Horst-Dieter
T1  - Binding Affinity and Capacity for the Uremic Toxin Indoxyl Sulfate
JF  - Toxins
N2  - Protein binding prevents uremic toxins from removal by conventional extracorporeal therapies leading to accumulation in maintenance dialysis patients. Weakening of the protein binding may enhance the dialytic elimination of these toxins. In ultrafiltration and equilibrium dialysis experiments, different measures to modify the plasma binding affinity and capacity were tested: (i), increasing the sodium chloride (NaCl) concentration to achieve a higher ionic strength; (ii), increasing the temperature; and (iii), dilution. The effects on the dissociation constant K-D and the protein bound fraction of the prototypical uremic toxin indoxyl sulfate (IS) in plasma of healthy and uremic individuals were studied. Binding of IS corresponded to one site binding in normal plasma. K-D increased linearly with the NaCl concentration between 0.15 (K-D = 13.2 +/- 3.7 mu M) and 0.75 M (K-D = 56.2 +/- 2.0 mu M). Plasma dilution further reduced the protein bound toxin fraction by lowering the protein binding capacity of the plasma. Higher temperatures also decreased the protein bound fraction of IS in human plasma. Increasing the NaCl concentration was effective to weaken the binding of IS also in uremic plasma: the protein bound fraction decreased from 89% +/- 3% to 81% +/- 3% at 0.15 and 0.75 M NaCl, respectively. Dilution and increasing the ionic strength and temperature enhance the free fraction of IS allowing better removal of the substance during dialysis. Applied during clinical dialysis, this may have beneficial effects on the long-term outcome of maintenance dialysis patients.
KW  - protein binding
KW  - hemodialysis
KW  - human serum albumin
KW  - dialyzer membrane
KW  - P-cresyl sulfate
KW  - removal
KW  - dialysate
KW  - progression
KW  - clearance
KW  - kidney disease;
KW  - protein-bound solutes
KW  - chronic kidney-disease
KW  - ionic strength
KW  - uremic toxin
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117486
VL  - 6
IS  - 2
ER  - 
TY  - JOUR
A1  - Dörhöfer, Lena
A1  - Lammert, Alexander
A1  - Krane, Vera
A1  - Gorski, Mathias
A1  - Banas, Bernhard
A1  - Wanner, Christoph
A1  - Krämer, Bernhard K.
A1  - Heid, Iris M.
A1  - Böger, Carsten A.
T1  - Study design of DIACORE (DIAbetes COhoRtE) - a cohort study of patients with diabetes mellitus type 2
JF  - BMC Medical Genetics
N2  - Background: Diabetes mellitus type 2 (DM2) is highly associated with increased risk for chronic kidney disease (CKD), end stage renal disease (ESRD) and cardiovascular morbidity. Epidemiological and genetic studies generate hypotheses for innovative strategies in DM2 management by unravelling novel mechanisms of diabetes complications, which is essential for future intervention trials. We have thus initiated the DIAbetes COhoRtE study (DIACORE). 
Methods: DIACORE is a prospective cohort study aiming to recruit 6000 patients of self-reported Caucasian ethnicity with prevalent DM2 for at least 10 years of follow-up. Study visits are performed in University-based recruiting clinics in Germany using standard operating procedures. All prevalent DM2 patients in outpatient clinics surrounding the recruiting centers are invited to participate. At baseline and at each 2-year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized online questionnaire and physical examination to determine incident micro-and macrovascular DM2 complications, malignancy and hospitalization, with a primary focus on renal events. Confirmatory outcome information is requested from patient records. Blood samples are obtained for a centrally analyzed standard laboratory panel and for biobanking of aliquots of serum, plasma, urine, mRNA and DNA for future scientific use. A subset of the cohort is subjected to extended phenotyping, e. g. sleep apnea screening, skin autofluorescence measurement, non-mydriatic retinal photography and non-invasive determination of arterial stiffness. 
Discussion: DIACORE will enable the prospective evaluation of factors involved in DM2 complication pathogenesis using high-throughput technologies in biosamples and genetic epidemiological studies.
KW  - chronic kidney-disease
KW  - stage renal-disease
KW  - glomerular-filtration-rate
KW  - genome-wide association
KW  - blood-glucose control
KW  - genetics
KW  - serum creatinine
KW  - cardiovascular disease
KW  - replacement therapy
KW  - United States
KW  - risk factors
KW  - diabetes mellitus type 2
KW  - diabetic nephropathy
KW  - end stage renal disease
KW  - cardiovascular morbidity
KW  - diabetes complications
KW  - epidemiology
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122040
SN  - 1471-2350
VL  - 14
IS  - 25
ER  -