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According to climate change scenarios, central Europe may expect extending drought periods during summer. Lower water availability may influence the ruminal digestion of individual forage legume species differently. To test this hypothesis, Lotus corniculatus L. (var. Bull), Medicago lupulina L. (var. Ekola), Medicago falcata L. (wild seeds) and Trifolium repens L. (var. Rivendel) were each grown in parallel lots of control and drought-stressed monocultures. Rainout shelters (installed in May 2011 on a regrowth after first cut until harvest in mid of June) withheld rainfall of 40 mm in the drought stress treatment. Samples of dried (60°C) and milled (5 mm screen) forage legumes were incubated in a simulation experiment using Rusitec to assess drought effects on parameters for microbial metabolism. Degradability of dry matter and organic matter as well as methane production decreased in incubations with drought-stressed compared to control variants of legume species. Degradability of crude protein, neutral detergent fibre, acid detergent fibre and residual organic matter including non-fibre carbohydrates and lipids were affected by interactions between drought stress and species. Significant interactions were also found for ammonia concentrations, molar SCFA proportions and the microbial communities. It is concluded that drought stress for growing forage legumes influences their ruminal degradation and fermentation as well as the ruminal microbial communities of Bacteria and Archaea differently in a legume species-dependent manner., (© 2019 Blackwell Verlag GmbH.)

Background: The natural history of malignancies, the response to cytokine-based therapy and survival of patients may be partly determined by the human leukocyte antigen (HLA) phenotype. Here, we investigated in a retrospective analysis the correlation of the HLA phenotype of 73 prognostic favored patients with advanced renal cell carcinoma to (a) the expected HLA distribution in Caucasians, (b) the susceptibility or resistance to metastatic sites, (c) response to cytokine-based therapy and (d) sustained cytokine-induced effective tumor control., Methods: We retrospectively determined the MHC class I and II antigens in patients with metastatic renal cell carcinoma selected by survival. Antigens were serologically typed by standard lymphocytotoxicity techniques. For statistical analysis, we calculated the probability of the presented HLA antigens in correlation to the expected Caucasian HLA phenotypes. An independent confirmation was performed by using the chi-square and two-tailed Fisher's exact test., Results: Various HLA antigens deviated significantly from the normal distribution in the Caucasian population. HLA.B44 was the only antigen associated (p < 0.01) with the absence of lung and presence of bone metastases, while it did not impact on overall survival or response to therapy. A1 (p < 0.0001, p < 0.002) and B8 (p < 0.009, p < 0.04) alleles were more frequently expressed in responding patients than expected from the normal distribution in Caucasians and that observed in non-responding patients, respectively. The HLA analysis of patients achieving a durable complete remission showed a significantly higher frequency of expression of the A1 and B8 antigens and furthermore of the B14 antigen (p < 0.05)., Conclusions: Our data underline the pivotal role of the MHC complex in controlling and regulating the cellular immune response in renal cell cancer. We could identify HLA antigens, which correlate with response to cytokine-treatment, with a long-lasting effective tumor control and prolonged overall survival.

The purpose of the present study was to determine the lead structure in cardiac glycosides at the receptor level, i.e. the minimal structural requirement for specific and powerful receptor recognition. Accordingly 73 digitalis-like acting steroids were characterized as to the concentration effecting half-maximum inhibition of Na,K-ATPase from human cardiac muscle under standardized turnover conditions. Since the Ki value equaled the apparent KD value, K'D was expressed in terms of the apparent standard Gibbs energy change delta G degrees' of steroid interaction with Na,K-ATPase. This allowed the use of the extrathermodynamic approach as a rational way of correlating in a quantitative manner, the potency and structure of the various steroidal compounds. The results of the present analysis taken in conjunction with relevant findings reported in the literature, favour the following conclusions. Cassaine, canrenone, prednisolone- and progesterone-3,20-bisguanylhydrazone, and chlormadinol acetate are compounds that are not congeneric with digitalis. The butenolide ring of cardenolides or the analogous side-chains at C17 beta of 5 beta, 14 beta-androstane-3 beta, 14-diol are not pharmacophoric substructures, but merely amplifiers of the interaction energy of the steroid lead. All modifications of the structure, geometry and spatial relationship between the steroid nucleus and butenolide side chain of digitoxigenin all at once weaken the close fit interaction with the steroid and butenolide binding subsites of the enzyme in such way that the cardenolide derivatives interact with the receptor binding site area in whatever orientation that will minimize the Gibbs energy of the steroid-receptor-solvent system. The "butenolide carbonyl oxygen distance model" (Ahmed et al. 1983) for the interpretation of the differences in potency of the cardenolide derivatives describes the change in interaction energy through structural modification as a function of the entire molecule. 5 beta, 14 beta-androstane-3 beta, 14-diol, the steroid nucleus of cardiac glycosides of the digitalis type, is the minimum structure for specific receptor recognition and the key structure for inducing protein conformational change and thus Na,K-ATPase inhibition. It is also the structural requirement for maximum contributions of the butenolide substituent at C17 beta and the sugar substituent at C3 beta-OH to the overall interaction energy, i.e. this steroid nucleus is the lead structure.(ABSTRACT TRUNCATED AT 400 WORDS)