@article{RailaForterreSchweigert2003, author = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.}, title = {Levels of retinol and retinyl esters in plasma and urine of dogs with urolithiasis}, year = {2003}, language = {en} } @article{RailaForterreSchweigert2003, author = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.}, title = {Die Bedeutung von Megalin in der Pathogenese der tubul{\"a}ren Proteinurie des Hundes}, isbn = {3-936815-65-8}, year = {2003}, language = {de} } @article{GerickeKoebnickReimannetal.2004, author = {Gericke, Beate and Koebnick, Corinna and Reimann, Manja and Forterre, Simone and Zunft, Hans-Joachim Franz and Schweigert, Florian J.}, title = {Influence of hormone replacement therapy on proteomic pattern in serum of postmenopausal women}, year = {2004}, abstract = {Objectives: Proteomics approaches to cardiovascular biology and disease hold the promise of identifying specific proteins and peptides or modification thereof to assist in the identification of novel biomarkers. Method: By using surface-enhanced laser desorption and ionization time of flight mass spectroscopy (SELDI-TOF-MS) serum peptide and protein patterns were detected enabling to discriminate between postmenopausal women with and without hormone replacement therapy (HRT). Results: Serum of 13 HRT and 27 control subjects was analyzed and 42 peptides and proteins could be tentatively identified based on their molecular weight and binding characteristics on the chip surface. By using decision tree-based Biomarker Patterns (TM) Software classification and regression analysis a discriminatory function was developed allowing to distinguish between HRT women and controls correctly and, thus, yielding a sensitivity of 100\% and a specificity of 100\%. The results show that peptide and protein patterns have the potential to deliver novel biomarkers as well as pinpointing targets for improved treatment. The biomarkers obtained represent a promising tool to discriminate between HRT users and non-users. Conclusion: According to a tentative identification of the markers by their molecular weight and binding characteristics, most of them appear to be part of the inflammation induced acute-phase response. (c) 2004 Elsevier Ireland Ltd. All rights reserved}, language = {en} } @article{RailaStohrerForterreetal.2004, author = {Raila, Jens and Stohrer, M. and Forterre, Simone and Stangassinger, M. and Schweigert, Florian J.}, title = {Effect of exercise on the mobilization of retinol and retinyl esters in plasma of sled dogs}, year = {2004}, abstract = {Fasting dogs do transport vitamin A (VA) in plasma not only as retinol but predominantly as retinyl esters. Contrary to retinol, nothing is known concerning the effects of athletic performance on plasma retinyl ester concentrations. The aim of this study was therefore to examine whether physical stress because of exercise and modification of the oxidative stress by supplementation of alpha-tocopherol influences the concentrations of retinol and retinyl esters in plasma of sled dogs. The study was carried out on 41 trained adult sled dogs, which were randomly assigned into two groups. One group (19 dogs) was daily substituted with 50 mg DL-alpha-tocopheryl acetate per kilogram body weight and the control group (22 dogs) was maintained on a basal diet during 3 months prior to exercise. The plasma concentrations of retinol, retinyl esters, alpha-tocopherol and triglycerides were measured immediately before, directly after and 24 h after exercise. The supplementation of alpha-tocopheryl acetate had no effect on plasma retinol and retinyl ester concentrations at any measurement time point. However, retinyl ester levels doubled in the non- supplemented group immediately after the race (p < 0.001), whereas in the supplemented group similar high levels were observed not until 24 h post-racing (p < 0.001). The high levels of retinyl esters were paralleled to some extent by an increase in plasma triglyceride concentrations, which were significantly higher 24 h post-racing than immediately before (p < 0.001) and after exercise (p < 0.001) in both groups. The increase in retinyl ester concentrations might be indicative of their mobilization from liver and adipose tissue. Whether plasma retinyl esters can be used as an indicator for the extent of nutrient mobilization during and post-exercise in sled dogs remains to be elucidated}, language = {en} } @article{ForterreRailaSchweigert2004, author = {Forterre, Simone and Raila, Jens and Schweigert, Florian J.}, title = {Protein profiling of urine from dogs with renal disease using ProteinChip analysis}, year = {2004}, abstract = {Measurement of total urinary proteins in individuals that tested positive by urinary dipstick is a typical method for assessing the presence of potentially serious renal disorders. In the absence of such overt proteinuria, however, measurement of specific urinary proteins may be useful in the diagnosis of nephropathies and may provide greater insight into the pathogenesis. The urine of 28 dogs (16 with renal disease and 12 healthy) was evaluated to determine whether specific low-molecular-weight proteins or the pattern of protein excretion could also be used as a marker of tubular dysfunction in dogs. Specific proteins were assessed by immunological methods, whereas protein profiles were determined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (MS). In particular, changes in the excretion of retinol-binding protein (RBP) and Tamm-Horsfall protein (THP) appear to be of clinical relevance in the diagnosis of canine kidney diseases. The pattern of urinary protein and peptides revealed specific changes in abundance in dogs with renal disease at molecular masses (kD) of 11.58, 12.41, 12.60, 14.58, 20.95 (RBP), 27.85, and 65.69 (albumin). In conclusion, comparable proteins as in humans might be used as urinary markers for proximal (RBP) and distal (THP) tubular dysfunction in dogs. Surface-enhanced laser desorption/ionization time-of-flight MS is a promising tool for the study of kidney physiology and pathophysiology and might aid in the discovery of new biomarkers of renal disease}, language = {en} } @article{RailaForterreSchweigert2005, author = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.}, title = {Physiology and pathophysiology of proteinuria : a review}, issn = {0005-9366}, year = {2005}, abstract = {The term proteinuria is taken to mean abnormally high protein excretion in the urine. Proteinuria is the consequence of glomerular filtration of plasma proteins, their subsequent reabsorption by the proximal tubular cells and secretion of protein by the tubular cells and distal urinary tract. In physiological conditions, the structural integry of the glomerular filtration barrier prevents the abnormal passage of albumin (molecular mass 66 kDa) and high-molecular- weight proteins (> 66 kDa),whereas the passage of low-molecular-weight proteins (< 66 kDa) is almost completely unrestricted. Proteins that arrive the tubular lumen are reabsorbed by endocytosis after binding to the megalin-cubilin complex. An increased load of proteins in the tubular lumen leads to the saturation of the reabsorptive mechanism and higher urinary protein excretion. Proteinuria can originate from prerenal, renal and postrenal causes. Elevated tubular protein concentrations have been recognized to be toxic to tubular cells and associated with the progression of chronic renal disease. Therefore, the quantitative and qualitative evaluation of proteinuria is important for the diagnosis of renal disease}, language = {en} } @article{RailaForterreSchweigert2005, author = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.}, title = {Physiologische und pathophysiologische Grundlagen der Proteinurie : eine {\"U}bersicht}, year = {2005}, language = {de} } @article{RailaForterreSchweigert2005, author = {Raila, Jens and Forterre, Simone and Schweigert, Florian J.}, title = {Markerproteine im Harn von Hunden}, isbn = {3-8304-1051-4}, year = {2005}, language = {de} } @article{ForterreRailaForterreetal.2006, author = {Forterre, Simone and Raila, Jens and Forterre, Franck and Brunnberg, Leo and Schweigert, Florian J.}, title = {Characterisation of transthyretin and retinol-binding protein in plasma and cerebrospinal fluid of dogs}, issn = {1090-0233}, doi = {10.1016/j.tvjl.2004.11.017}, year = {2006}, abstract = {The aim of this study was to investigate differences in concentrations of vitamin A, transthyretin (TTR) and retinol-binding protein (RBP) between plasma and cerebrospinal fluid (CSF) in dogs. RBP was detected using ELISA, and both RBP and TTR by Western blot analysis after separation on SDS-PAGE. Vitamin A was determined by high performance liquid chromatography. RBP and TTR as well as vitamin A were detected in all samples but at substantially lower concentrations in CSF compared to plasma. RBP in dog plasma showed a similar molecular mass to that of humans, whereas canine TTR had a lower molecular mass. Comparison between plasma and CSF showed that both RBP and TTR were of lower molecular mass in CSF. In CSF, RBP and retinol were present at 10-100-fold lower concentrations compared to plasma. Retinyl esters were present only in minute amounts in 5/17 samples. In conclusion, the CSF of dogs compared to humans is significantly different in terms of both quality and quantity of transport proteins for vitamin A.}, language = {en} } @article{ForterreRailaKohnetal.2006, author = {Forterre, Simone and Raila, Jens and Kohn, Barbara and Brunnberg, Leo and Schweigert, Florian J.}, title = {Protein profiling of organic stone matrix and urine from dogs with urolithiasis}, issn = {0931-2439}, doi = {10.1111/j.1439-0396.2005.00590.x}, year = {2006}, abstract = {Two-thirds of the organic matrix in urinary stones consists of proteins. Their relationship to calculogenesis remains controversial with regard to their effect as inhibitors or promoters during stone formation. The purpose of the present study was to determine the differences in peptide and protein pattern between the urine of stone formers (n = 23) and control dogs (n = 12), as well as between organic matrix of different urinary stones (struvite n = 11, calcium oxalate n = 8, uric acid n = 4) using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Specific differences in protein and peptide profiles were found in the organic matrix of different mineral compositions. Characteristic differences were also found in urinary peptide and protein pattern especially in molecular masses below 20 kDa between affected and healthy dogs. Based on the obtained molecular masses they were in some cases tentatively identified as proteins that are known to be involved in stone formation in humans. The study shows that in dogs, specific-urinary peptides and proteins might be associated with urolithiasis. It indicates the importance to further characterize those proteins for possible diagnostic purposes in prognosis and therapy}, language = {en} }