Human leukocyte antigen distribution in German Caucasians with advanced Ewing's sarcoma.

BACKGROUND: Risk stratification criteria for patients with Ewing's sarcoma family of tumors (ESFT) are still limited. We hypothesized divergent human leukocyte antigen (HLA) patterns in ESFT patients and compared HLA-A, -B and -DR phenotype frequencies of patients with advanced ESFT with those of healthy controls. PATIENTS: HLA types of all German Caucasian patients with advanced ESFT and available HLA-A, -B and -DR data registered in the European Group for Blood and Marrow Transplantation, Paediatric Registry for Stem Cell Transplantation and the MetaEICESS data bases (study group, n=30) were retrospectively compared with HLA types of healthy German stem cell donors (control group, n=8 862 for single HLA frequencies and n=8 839 for allele combinations). Study group patients had been immuno-typed due to eligibility for allogeneic stem cell transplantation for high risk of treatment failure, and thus constituted a selected subgroup of ESFT patients. RESULTS: After Bonferroni correction for multiple testing (PC), phenotype frequencies of HLA-A24 remained significantly higher in the study group compared to controls (PC<0.05). Furthermore, several HLA combinations were significantly more frequent in the study group compared to controls (all PC<0.05). CONCLUSION: We report an increased incidence of circumscribed HLA patterns in German Caucasians with advanced ESFT. The possible clinical significance of this observation has to be re-assessed in prospective trials comprising larger ESFT patient numbers of all risk groups.

High STEAP1 expression is associated with improved outcome of Ewing's sarcoma patients.

BACKGROUND: Ewing's sarcoma (ES) is the second most common bone or soft-tissue sarcoma in childhood and adolescence and features a high propensity to metastasize. The six-transmembrane epithelial antigen of the prostate 1 (STEAP1) is a membrane-bound mesenchymal stem cell marker highly expressed in ES. Here, we investigated the role of STEAP1 as an immunohistological marker for outcome prediction in patients with ES. PATIENTS AND METHODS: Membranous STEAP1 immunoreactivity was analyzed using immunohistochemistry in 114 primary pre-chemotherapy ES of patients diagnosed from 1983 to 2010 and compared with clinical parameters and patient outcome. Median follow-up was 3.85 years (range 0.43-17.51). RESULTS: A total of 62.3% of the ES samples displayed detectable STEAP1 expression with predominant localization of the protein at the plasma membrane. High membranous STEAP1 immunoreactivity was found in 53.5%, which correlated with better overall survival (P=0.021). Accordingly, no or low membranous STEAP1 expression was identified as an independent risk factor in multivariate analysis (hazard ratio 2.65, P=0.036). CONCLUSION: High membranous STEAP1 expression predicts improved outcome and may help to define a specific subgroup of ES patients, who might benefit from adapted therapy regimens.

Specific recognition and inhibition of Ewing tumour growth by antigen-specific allo-restricted cytotoxic T cells.

BACKGROUND: The development of a successful immunotherapy is hampered by an ineffective T-cell repertoire against tumour antigens and the inability of the patient's immune system to overcome tolerance-inducing mechanisms. Here, we test the specific recognition and lytical potential of allo-restricted CD8(+) T cells against Ewing tumour (ET) associated antigens Enhancer of Zeste, Drosophila Homolog 2 (EZH2), and Chondromodulin-I (CHM1) identified through previous microarray analysis. METHODS: Following repetitive CHM1(319) (VIMPCSWWV) and EZH2(666) (YMCSFLFNL) peptide-driven stimulations with HLA-A 0201(+) dendritic cells (DC), allo-restricted HLA-A 0201(-) CD8(+) T cells were stained with HLA-A 0201/peptide multimers, sorted and expanded by limiting dilution. RESULTS: Expanded T cells specifically recognised peptide-pulsed target cells or antigen-transfected cells in the context of HLA-A 0201 and killed HLA-A 0201(+) ET lines expressing the antigen while HLA-A 0201(-) ET lines were not affected. Furthermore, adoptively transferred T cells caused significant ET growth delay in Rag2(-/-)γ(C)(-/-) mice. Within this context, we identified the CHM1(319) peptide as a new candidate target antigen for ET immunotherapy. CONCLUSION: These results clearly identify the ET-derived antigens, EZH2(666) and CHM1(319), as suitable targets for protective allo-restricted human CD8(+) T-cell responses against non-immunogenic ET and may benefit new therapeutic strategies in ET patients treated with allogeneic stem cell transplantation.

Only therapeutic ICOS:ICOSL blockade alleviates acute graft versus host disease.

Inducible co-stimulator (ICOS) interaction with its ligand (ICOSL) is involved in several T cell effector functions. While blockade of ICOS:ICOSL interaction in chronic graft versus host disease (GVHD) seems beneficial, results for acute GVHD remain controversial. To further elucidate its role in acute GVHD, C57BL/6 mice were reconstituted with allogeneic spleen cells in the absence or presence of ICOSL-blocking mAb. Mice reconstituted with allogeneic spleen cells experienced severe GVHD and died untreated within 6-9 days after transplantation. Mice treated with an anti-ICOSL mAb starting from day 3 after transplantation gained weight again and survived for at least additional 12 days, although the treatment was already stopped at day 11 after transplantation. In contrast, the anti-ICOSL treatment starting from day 0 did not prevent GVHD. The difference between therapeutic (day 3) and prophylactic (day 0) anti-ICOSL treatment was independent of CD25+CD4+ regulatory T cells since their depletion did not abrogate the therapeutic effect of ICOSL blockade. Microarray analysis revealed IFN-gamma and chemokine up-regulation in spleen cells of prophylactically treated mice, emphasizing kinetic dependence of acute GVHD modulation via blockade of ICOS:ICOSL interaction.

CD25 blockade protects T cells from activation-induced cell death (AICD) via maintenance of TOSO expression.

CD25 monoclonal antibody binding to the alpha-chain of the Interleukin-2 (IL-2) receptor, blocks high-affinity IL-2 binding, thereby preventing complete T-cell activation and being of ample importance in transplantation medicine and potentially the treatment of autoimmune disease. However, CD25 antibodies do not only block T-cell activation but also prevent activation-induced cell death (AICD) attributing a dual function to IL-2. In this study, the modulation of the genomic expression profile of human peripheral blood mononuclear cells (PBMC) with therapeutic concentrations of humanized anti-CD25 mAb was investigated. PBMC were stimulated with CD3 antibody OKT-3 together with recombinant IL-2 in the absence or presence of anti-CD25 mAb. RNA was extracted and subjected to microarray analysis on U133A microarrays (Affymetrix). Anti-CD25 treatment inhibited several genes typically expressed during T-cell activation including granzyme B, signalling lymphocyte activation molecule, family member 1 (SLAMF1), CD40-Ligand (CD40-L), IL-9 and interferon (IFN)-gamma. Interestingly, anti-CD25 mAb also blocked the expression of several genes important for susceptibility to apoptosis, such as death receptor 6 (DR6) or reversed IL-2-mediated repression of anti-apoptotic genes, such as Fas apoptotic inhibitory molecule 3 (FAIM3)/TOSO. Functional significance of DR6 and TOSO expression in IL-2-dependent T-cell activation was subsequently evaluated by RNA interference in AICD: While siRNA specifically directed against DR6 did not modulate FAS-L-mediated apoptosis induction in primary T cells, down-regulation of TOSO significantly increased susceptibility to apoptosis, emphasizing an important role for TOSO in IL-2-mediated AICD.

In vitro testing of the bond between soft materials used for maxillofacial prostheses and cast titanium.

STATEMENT OF PROBLEM: The choice of soft materials for maxillofacial prostheses is important for covering extraoral defects after tumor surgery or radiation therapy. The use of cast commercially pure titanium as reinforcement seems to be a suitable option. PURPOSE: Making use of the advantages of titanium frameworks for maxillofacial prostheses requires exploring ways of combining it with soft materials. This study investigated such combinations and evaluated discoloration of the soft material to determine whether it was attributable to the titanium reinforcement. MATERIAL AND METHODS: Five soft materials used for maxillofacial prostheses and their bond strengths to cast titanium were tested. Different ways of conditioning the titanium surface and different adhesives were used. Plain mechanical retention was also studied. The Gretag SPM 100 was used to determine the potential effects on coloring after 24 hours of radiation in the Suntest rapid exposure unit. RESULTS: Suitable material combinations for bonding soft materials to titanium were found for all soft materials studied. Bond strength varied depending on the chemical basis of the soft material. Results indicated that maximal bond strengths were obtained by the combinations Supersoft with Super-Bond, Supersoft with subsequent silicoating, and bonding with Dentacolor connector. Few color shifts attributable to the titanium reinforcement were evident in the 2-mm layers of the soft materials applied. CONCLUSION: The results of this study showed that it is possible to combine a titanium framework and soft silicone materials.

[Effect of various sources of phosphorus on the apparent digestibility of crude nutrients, growing and slaughtering performance as well as selected parameters of metabolism in fattening bulls]. / Einfluss unterschiedlicher Phosphorgaben auf die scheinbare Verdaulichkeit der Rohnährstoffe, Mast- und Schlachtleistung sowie ausgewählte Stoffwechselparameter von Jungmastbullen.

Two long-term individual feeding experiments (336 and 307 days) were carried out with 52 (experiment I; Black and White dairy cattle) and 22 (experiment II; Yellow cattle) growing bulls. Rations varied in P-content. In experiment I straw: concentrate-mixture (1:2.5) were fed, phosphorus content of rations amounted to 2, 3 or 4 g/kg DM. In experiment II maize silage was fed ad lib. supplemented with 2.4 kg concentrate per animal per day. P-content of rations amounted to 3 and 4 g/kg DM. Apparent digestibility of rations was determined during experiments. Blood samples were taken to analyse selected parameters of metabolism. Various P-supply did not significantly influence apparent digestibility of organic matter and crude nutrients in both experiments. Bulls fed 2 g P/kg DM decreased DMI in experiment I already after 50 days of experiment. After 168 experimental days daily weight gain of bulls fed with 2 g P/kg DM was 124 or 132 g lower than that of bulls fed with 3 or 4 g P/kg DM respectively. P-concentration of inorganic P in serum decreased to < 2 mmol/l, bone mineralisation was reduced. There exist no significant differences in feed intake, weight gain and metabolic parameters of bulls fed with 3 or 4 g P/kg DM. Increase of P-supply from 2 to 3 or 4 g/kg DM compensated partially the lower weight gain. Application of 3 or 4 g P/kg DM in experiment II effected daily weight gains of > 1200 g and did not significantly influence all investigated criterions.

[Influence of the ration content on the fecal phosphorus excretion of growing bulls varying in body weight]. / Einfluss der Rationsgestaltung auf die faecale Phosphorausscheidung bei unterschiedlich schweren Mastbullen.

Five smaller (body weight: 227.9 +/- 23.7 kg) and large growing bulls (435.2 +/- 14.3 kg per animal) each were fed with rations rich (chopped wheat straw:concentrate = 1:1) or poor in roughage (straw: concentrate = 1:4). Animals were kept in balance cages; 20 days adaptation period were followed by 10 days collection period. Body weight of bulls did not significantly influence apparent digestibility of rations. digestibility of organic matter of fibre rich ration was significantly lower (66.8%) than those of concentrate rich ration (74.4%). Feeding and body weight did not significantly influence metabolic parameters of mineral status. The fecal P-excretion amounted to 0.94 and 1.08 g per kg DMI in bulls fed with rations rich and poor in roughage. No influence of body weight was measured. Feeding and body weight did not significantly influence fecal P-excretion per kg DOMI (between 1.44 and 1.58 g P/kg DOM). For calculation of P-requirements for growing cattle fecal P-excretion amounted to 1.0 or 1.5 g P/kg DM and DOMI, respectively.

[Effect of rapeseed in beef cattle feeding on fatty acid composition, vitamin E content and oxidative stability of body fat]. / Einfluss von Rapssamen in der Mastrinderernährung auf Fettsäurenmuster, Vitamin-E-Gehalt und oxidative Stabilität des Körperfettes.

Four groups of five fattening bulls each consumed a concentrate--wheat straw-diet (2.5:1) supplemented with either 0, 7, 14 or 21% ground rape seed for 350 days. Rape seed contained 427 g crude fat (ether extract) and 127 mg vitamin E per kg dry matter. The supplementation with rapeseed increased the fat concentrations in the rations from 25 to 50, 75 and 100 g, and of vitamin E from 11 to 19, 26 and 34 mg per kg dry matter. All bulls were slaughtered with about 560 kg body weight. Fatty acid composition of depot fat and of the fat of musc. long. dorsi were determined by gas liquid chromatography. Vitamin E concentrations in blood, depot fat and muscle were determined by HPLC. Oxidative stability of depot fat was measured as induction time by means of rancimat-test. Rape seed supplementation decreased C16-fatty acids and increased C18-fatty acids in depot and muscle fat. Muscle fat contained significantly more mono and poly unsaturated fatty acids (40.2 and 7.4%) than depot fat (33.5 and 2.0%, respectively). Rape seed supplementation enhanced significantly the vitamin E-concentrations in all body samples. In depot fat vit. E increased from 4.5 to 7.3, 8.5 and 14.9 micrograms/g. Induction time increased from 10.9 to 18.5, 16.1 and 19.5 h, when 0, 7, 14 or 21% rapeseed were added.

[Effect of flavomycin on the apparent digestibility of crude nutrients in wethers, parameters of rumen fermentation in cattle and feed intake and weight gain of heifers]. / Einfluss von Flavomycin auf die scheinbare Verdaulichkeit der Rohnährstoffe bei Hammeln, Kennzahlen der Pansenfermentation bei Rindern sowie Futteraufnahme und Lebendmassezunahme weiblicher Jungrinder.

Three experiments with five wether each were carried out in order to investigate the influence of various levels of flavomycin (0, 5 and 10 mg per animal and day) on apparent digestibility of artificially dried grass. A short time individual feeding experiment (42 days) with 9 bulls and a long term individual feeding experiment (225 days) with 52 heifers were conducted. Animals consumed 0 or 30 mg flavomycin per day. Parameters of rumen fermentation were investigated. Feed intake and weight gain were measured in the experiment with heifers. Flavomycin did not significantly influence the apparent digestibility of organic matter and crude nutrients as well as parameters of rumen fermentation. Flavomycin did not influence dry matter intake, but increased significantly weight gain (49 g per animal and day, 10.5%) and reduced feed and energy required per kg weight gain (10.6%) in heifers. The reasons of ergotropic effects of flavomycin are mostly unknown at present.

[Effect of graduated vitamin D3 doses and different ration composition on the 25OH-vitamin D3 plasma concentration and fattening and slaughter production of bulls]. / Einfluss gestaffelter Vitamin-D3-Gaben und unterschiedlicher Rationsgestaltung auf die 25OH-Vitamin-D3-Plasma-Konzentration sowie Mast- und Schlachtleistung von Mastbullen.

In a individual feeding experiment (348 days) 24 fattening bulls were given either a ration high in roughage (2.8 kg concentrate mixture, wheat straw ad libitum: group I) or high in concentrate (5.6 kg concentrate mixture, wheat straw ad libitum group II) supplemented with various levels of vitamin D3 (0, 250, 500, 1,000, 2,000, 4,000 and 8,000 IU per 100 kg body weight (bw) and day) and minerals as required. After 58, 101, 134, 172, 205, 277 and 340 days 25-OH-D3 plasma concentration was estimated. Fattening and slaughtering parameters were measured. The 25OH-D3 plasma concentration was significantly influenced by vitamin D3 supply, kind of ration and day of taking samples. 25-OH-D3 plasma concentration decreased below 5 ng per ml when vitamin D3 supply was less than or equal to 250 IU per 100 kg bw and day. The initial plasma levels were maintained when 500 IU vitamin D3 per 100 kg bw and day was given (6.6 ng per ml). Administration of greater than or equal to 1,000 IU per 100 kg bw and day increased 25OH-D3 plasma level (greater than 10 ng/ml). Plasma 25OH-D3 concentration was significant higher when bulls consumed diets rich in concentrate (10.6 and 18.2 ng/ml for I and II after 340th day). Differences in content of cell walls and crude fat of rations may be responsible for results. Daily weight gain of bulls amounted to 712 and 945 g when fed diets I or II. Dry matter intake and live weight gain were not significantly influenced by different vitamin D3 supply. Clinical symptoms of rachitis did not appear.

[The effect of salinomycin on apparent digestibility, indices of rumen fermentation and fattening and slaughter yields of cattle]. / Einfluss von Salinomycin auf scheinbare Verdaulichkeit, Kennzahlen der Pansenfermentation sowie Mast- und Schlachtergebnisse von Mastrindern.

The influence of salinomycin (0, 15, 30 and 60 mg per animal and day) on apparent digestibility of artificially dried grass was investigated in four experiments with five wether each. Three long term individual feeding experiments (210 to 252 days) with 72 growing bulls were carried out. The influence of various salinomycin levels (100 to 300 mg per animal and day) were investigated on parameters of rumen fermentation as well as fattening and slaughtering results. Salinomycin decreased insignificantly (P greater than 0.05) the apparent digestibility of organic matter (71.0; 70.1; 68.7 and 68.4%) and crude carbohydrates (71.8; 70.3; 69.2 and 68.5% resp.). The digestibility of other nutrients was not influenced. Supplementation of salinomycin reduced molar concentration of acetate (49 to 115) and butyrate (22 to 82) and increased propionate (110 to 199 mmoles per mol) in rumen liquid. Dry matter intake of bulls declined (0.8%, 13.5 and 24.6; 4.7% of experiments 1 to 3) when salinomycin was added. Daily weight gain (6.5 and 1.0%) and feed efficiency (6.8 and 6.3%) of bulls supplemented with salinomycin were improved in experiments 1 and 3. Significant decrease of feed intake of bulls of experiment 2 affected decline of weight gain probably as consequence of high salinomycin levels. Slaughtering results (except experiment 2) and body composition of bulls were not significantly influenced by salinomycin. Under consideration of own results and some references 10 to 20 mg per kg dry matter or 50 to 150 mg salinomycin per fattening bull and day are recommended as optimal level.

[The effectiveness of oral and parenteral vitamin A doses in growing cattle with different vitamin A supplies]. / Untersuchungen zur Effektivität oraler und parentaler Vitamin-A-Gaben bei unterschiedlich mit Vitamin A versorgten wachsenden Rindern.

The effect of one single oral or parenterally administered dose of 1 million IU vitamin A on the vitamin A depot in the liver and on blood plasma vitamin A concentrations was investigated in 3 individual feeding experiments with involvement of 18 and 24 calves or 24 fattening bulls. 50% of all animals in each of the 3 experiments received feed without any vitamin A through 108 or 112 or 209 days, prior to vitamin A administration, or received 10.000 IU/100 kg live weight and day. Parenteral vitamin A administration in either group yielded rise in blood plasma from 0.06--0.35 to 26.2--30.2 mumol/l, after 1 or 2 days. The maximum value measured after oral administration was 1.9 mumol/l. Most of the plasma values had returned to normal (0.6--12. mumol/l) within 14 days from administration. Oral and parenteral vitamin A doses, after 14 days, caused significant rise in vitamin A concentrations in the liver (from 15.5 to 82.5), with the increase resulting from parenteral administration (from 13.7 to 99.1) being clearly higher than that resulting from oral administration (from 17.3 to 65.9 mumol/kg fresh liver tissue). The same trends were recorded from recovery of vitamin A from the liver (26.8% after parenteral administration versus 15.0% in the wake of oral doses). Storage in and recovery from vitamin-A depleted animals were below values recorded from young cattle with sufficient vitamin A supply. These findings are likely to confirm that one single parenteral vitamin A administration was of clearly higher effectiveness, as compared to oral application.

[The effect of avoparcin on apparent digestibility, characteristics of rumen fermentation and fattening and slaughter output of growing cattle]. / Untersuchungen zum Einfluss von Avoparcin auf scheinbare Verdaulichkeit, Kennzahlen der Pansenfermentation sowie Mast- und Schlachtleistung wachsender Rinder.

Four digestion experiments with 5 wethers each (0, 15, 30 or 60 mg avoparcin per animal and day), three individual feeding experiments (28, 18 or 56 bulls per experiment; 0 and 150/200; 0, 250 and 500 or 0 and 200 mg avoparcin per animal and day in the experiments 1, 2 or 3) and two group feeding experiments (60 bulls and 161 heifers per experiment; salt lick stones without or with 2.5 g avoparcin per kg) were carried out in order to investigate the influence of avoparcin on apparent digestibility, figures of rumen fermentation, fattening and slaughtering results as well as protein, fat and energy retention. Avoparcin supplementation did not significantly influence the apparent digestibility of organic matter and crude nutrients. Concentration of acetate of rumen liquid was decreased (16 or 36) and that of propionate was increased (25 or 50 mmoles per mol) when 200 or 500 mg avoparcin per animal and day were added. Acetate:propionate ratio decreased from 4.2 to 3.5 and 3.1:1. Avoparcin did not influence feed intake, enhanced daily weight gain (37 to 174 g per animal and day) and improved feed efficiency (5 to 26%). Salt lick stones with avoparcin increased weight gain (58 and 96 g per animal and day). Slaughtering results and body composition of bulls were not influenced by avoparcin. Daily retention of protein, fat and energy was significantly increased (16 to 18%; P less than 0.05) when avoparcin was supplemented.

[The effect of lasalocid on apparent digestibility, characteristics of rumen fermentation and fattening and slaughter output of bulls]. / Einfluss von Lasalocid auf scheinbare Verdaulichkeit, Kennzahlen der Pansenfermentation sowie Mast- und Schlachtleistung von Bullen.

Four digestion experiments with 5 wethers each (Feeding: artificially dried grass; 0, 15, 30 or 60 mg lasalocid per animal and day), two short time experiments (Exp. 1: 3 rumen fistulated sheep; feeding; artificially dried grass; 0, 15, 30 or 60 mg lasalocid per animal and day; exp. 2: 20 bulls; feeding; 2 kg concentrates per animal and day; wheat straw ad libitum; 0, 150 or 300 mg lasalocid per animal and day) and one individual feeding experiment (24 bulls per group; duration: 279 days, feeding: 2 kg concentrates per animal and day, corn silage and whole barley-grass silage ad libitum; 0 or 100/200 mg lasalocid per animal and day) were carried out in order to investigate the influence of the ionophore lasalocid on digestibility, figures of rumen fermentation as well as fattening and slaughtering results of bulls. Higher doses of lasalocid (30 and 60 mg per animal and day) decreased significantly digestibility of organic matter (1.8 and 2.8 units) and crude fibre (5.8 and 7.2 units). Relative acetate (22 to 120 mmoles per mol) and butyrate concentration (23 to 58 mmoles per mol) were decreased and molar propionate concentration of rumen liquid (25 to 154 mmoles per mol) was increased depending on level of lasalocid supplementation. Lasalocid did not significantly influence the dry matter intake; daily weight gain and slaughtering results were increased (4.4 and 6.1%), energy efficiency was improved (3.8%). Effects of lasalocid are similar to that of monensin. A dose of 20 to 30 mg lasalocid per kg dry matter is recommended.

[The effect of a monensin-containing bolus on the live weight increase and characteristics of rumen fermentation of growing cattle]. / Untersuchungen zum Einfluss eines monensinhaltigen Bolus auf die Lebendmassezunahme und Kennzahlen der Pansenfermentation wachsender Rinder.

Eight feeding experiments (4 on pasture and indoors each) with 401 growing cattle were carried out in order to measure the influence of a monensin device on daily weight gain. The monensin device effected on the average 7 g (1.4%) and 37 g (4.3%) higher daily weight gain on pasture and indoors resp. (P greater than 0.05). The weight gain of animals varied between 92.5 and 112.5% compared with the unsupplemented groups. The monensin device caused a higher weight gain of easier cattle than of heavier ones (greater than 300 kg body weight). The device has had no significant effect on figures of rumen fermentation. Probably the monensin level delivered from the device (100 +/- 50 mg per animal and day) is to low for heavier cattle.

[The effect of various Ca and P supplies on the metabolic parameters of wethers and bulls and on the fattening performance of bulls with vitamin D deficiency]. / Einfluss unterschiedlicher Ca- und P-Versorgung auf Stoffwechselparameter von Hammeln und Bullen sowie auf die Mastleistung von Bullen bei Vitamin-D-Mangel.

The influence of different Ca- and/or P-supply on metabolic parameters and Ca-resp. P-balance was tested in 12 balance trials with mature wethers at different feeding regimes. Furthermore the influence of dietary Ca-excess on metabolic parameters and fattening performance of bulls was also tested. Increasing the P-intake at normal Ca-supply (Ca/P-ratio 1:1.7 ... 3.6) or at Ca-excess (Ca/P-ratio approximately 1.6:1) led to a higher P-concentration in blood and urine and lowered the Ca-content in serum as well as the apparent Ca-balance. These effects were greater in the ration rich in concentrate than in the ration rich in roughage. Increasing the dietary Ca-intake (Ca/P-ratio approximately 3.6:1) had no influence on metabolic parameters of wethers. In a vitamin-D-deficiency trial the Ca supplementation (Ca/P-ratio approximately 4.2:1) improved the performance of bulls and retarded the incidence of signs of rickets (lower feed intake, higher concentration of alkaline phosphatase in serum, lower bone mineralisation) for about 100 days compared with the control group (Ca/P ratio: 1.2:1).

[Methodologic recommendations for the determination of 25-OH vitamin D3 in plasma using HPLC]. / Methodische Hinweise zur Bestimmung von 25-OH D3-Vitamin im Plasma mittels HPLC.

A method for measuring 25-OH D3-vitamin (calcidiol) in plasma samples of cattle is described. The samples were purified using non-polar C 18-cartridges and 25-OH D3 was determined by high-performance liquid chromatography (HPLC) on a silicic acid straight phase liquid chromatography column (retention time 11.5 min). The detection limit for 25-OH D3 is about 0.5 ng injection quantity, the average recovery was 90%, the standard error amounted to 8%.