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Braun B.C.,Charite - Medical University of Berlin | Braun B.C.,Leibniz Institute For Zoo Und Wildtierforschung | Meyer H.-A.,Charite - Medical University of Berlin | Reetz A.,Charite - Medical University of Berlin | And 2 more authors.
Journal of Steroid Biochemistry and Molecular Biology | Year: 2010

Corticosteroid-binding globulin (CBG, transcortin) belongs to the serpin family of serine protease inhibitors (SERPINA6) and is mainly secreted by the liver. The negative acute phase protein CBG regulates free cortisol levels in the blood and distributes cortisol to its target tissues. So far no CBG serpin partner protease has been identified. However, its cleavage by human neutrophil elastase destroys ligand binding capacity and supposedly liberates cortisol at sites of inflammation. Here we report on the recombinant expression and secretion of human wild-type CBG and several novel mutants by human 293-EBNA cells. Functional characterization of wild-type and mutant CBG revealed distinct differences in ligand binding sensitivity to heat or elastase. Certain mutants are almost devoid of cortisol binding activity (Q232R and CBG Lyon), some display higher sensitivity for heat inactivation (G335V, Q232R and CBG Lyon) or for elastase cleavage (G335V). CBG mutant T342A is more resistant to elastase cleavage. Our data support the validity of the serpin structural concept. The expression system used provides functionally active human recombinant transcortin for further functional characterization of wild-type and human CBG mutant variants, which have been associated with altered serum free cortisol levels or pathophysiological constellations such as increased body weight, fatigue or hypotension. © 2010 Elsevier Ltd. Source


Matuszak A.,Max Planck Institute for Ornithology (Radolfzell) | Voigt C.C.,Leibniz Institute For Zoo Und Wildtierforschung | Storch I.,Albert Ludwigs University of Freiburg | Bauer H.-G.,Max Planck Institute for Ornithology (Radolfzell) | Quillfeldt P.,Max Planck Institute for Ornithology (Radolfzell)
Rapid Communications in Mass Spectrometry | Year: 2011

Macrophytes are at the base of many lake food webs providing essential food resources for animals at higher trophic level, such as invertebrates, fish and waterbirds. However, data regarding the spatiotemporal variation in isotopic composition of macrophytes are generally missing. We measured the carbon and nitrogen stable isotope ratios of Charophytes at Lake Constance, where they constitute a major food source for waterbirds. Our data reveal seasonal and site-specific differences as well as depth-specific variations in isotopic carbon values within the littoral zone. Charophytes were enriched in 13 C at sites of higher productivity: the δ13C values were high in summer, at shallow and at relatively nutrient-rich sites, and comparatively low in winter, and in deeper and nutrient-poorer sites. In contrast, no temporal or spatial trend was found to explain the variability in the isotopic nitrogen values. These results imply that the seasonal timing of food intake (relative to turnover rates of consumers tissue) and the potential depth of foraging need to be taken into account when calculating the relative contribution of energy sources to diets of consumers such as waterbirds. Copyright © 2011 John Wiley & Sons, Ltd. Source


Muller K.,Leibniz Institute For Zoo Und Wildtierforschung | Koster S.,Leibniz Institute For Zoo Und Wildtierforschung | Painer J.,Leibniz Institute For Zoo Und Wildtierforschung | Soderberg A.,National Veterinary Institute SVA | And 5 more authors.
European Journal of Wildlife Research | Year: 2014

Seasonal variation in reproduction is common in mammals as an adaptation to annual changes in the habitat. In lynx, male reproduction activity is of special interest because female lynxes are monoestric with an unusual narrow (about 1 month) breeding season. In Eurasian lynx, mating occurs between January and April depending on the latitude. To characterize the seasonal pattern of sperm and testosterone production in free-ranging Eurasian lynxes, long-term frozen-stored testis material obtained postmortem from 74 hunted or road-killed lynxes in Sweden was used to analyze annual changes in testis mass, testicular testosterone content, and spermatogenetic activity. Values of most gonadal parameters obtained in subadult lynxes were significantly different from the values observed in adult males. In adult lynxes, a moderate annual fluctuation of gonadal parameters was found which was most profound for testis weight and testicular testosterone concentration reaching highest values in March (median of 2.18 g and 2.67 μg/g tissue respectively). Grouping the data of pre-/breeding (January-April) and postbreeding season (May-September) revealed significant changes in testis weight and testosterone concentration. The relative spermatogenetic activity remained high in postbreeding testes. However, net sperm production decreased according to reduction of testis mass and a tendency to lower cauda epididymal sperm numbers in the postbreeding period was observed. Our results demonstrate that it is possible to analyze the gonadal activity of frozen testis/epididymis tissue postmortem and that male Eurasian lynxes show-opposite to the females-only moderate seasonal changes in their reproductive capacity. © 2014 Springer-Verlag Berlin Heidelberg. Source


Smitz J.,Center for Reproductive Medicine | Dolmans M.M.,Catholic University of Leuven | Donnez J.,Catholic University of Leuven | Fortune J.E.,Cornell University | And 9 more authors.
Human Reproduction Update | Year: 2010

Background: Female cancer patients are offered 'banking' of gametes before starting fertility-threatening cancer therapy. Transplants of fresh and frozen ovarian tissue between healthy fertile and infertile women have demonstrated the utility of the tissue banked for restoration of endocrine and fertility function. Additional methods, like follicle culture and isolated follicle transplantation, are in development. methods: Specialist reproductive medicine scientists and clinicians with complementary expertise in ovarian tissue culture and transplantation presented relevant published literature in their field of expertise and also unpublished promising data for discussion. As the major aims were to identify the current gaps prohibiting advancement, to share technical experience and to orient new research, contributors were allowed to provide their opinioned expert views on future research. results: Normal healthy children have been born in cancer survivors after orthotopic transplantation of their cryopreserved ovarian tissue. Longevity of the graft might be optimized by using new vitrification techniques and by promoting rapid revascularization of the graft. For the in vitro culture of follicles, a successive battery of culture methods including the use of defined media, growth factors and three-dimensional extracellular matrix support might overcome growth arrest of the follicles. Molecular methods and immunoassay can evaluate stage of maturation and guide adequate differentiation. Large animals, including non-human primates, are essential working models. conclusions: Experiments on ovarian tissue from non-human primate models and from consenting fertile and infertile patients benefit from a multidisciplinary approach. The new discipline of oncofertility requires professionalization, multidisciplinarity and mobilization of funding for basic and translational research. © The Author 2010. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. Source


Henry F.,National Veterinary School of Alfort | Eder S.,Leibniz Institute For Zoo Und Wildtierforschung | Reynaud K.,CNRS Physiology of Reproduction and Behaviors | Schon J.,Leibniz Institute For Nutztierbiologie | And 3 more authors.
Theriogenology | Year: 2015

From many endangered or threatened species which are expected to profit from assisted reproduction techniques, mainly epididymal sperm of dead or freshly castrated males are available. These sperm had contact to epididymal secretion products but not to seminal fluid components. Notably, products of accessory sex glands have been shown in domestic animals to condition sperm for fertilization, in particular by mediating sperm-oviduct interaction. We report for the first time that motile epididymal sperm from domestic cats are able to bind to fresh oviduct epithelial cell explants from preovulatory females (median [min, max] of 10 [8, 16] and 10 [8, 17] sperm per 0.01mm2 explant surface from both isthmic and ampullar regions, respectively). More sperm attach to the explants when epididymal sperm were preincubated for 30minutes with seminal fluid separated from electroejaculates of mature tomcats (median [min, max] of 17 [13, 25] and 16 [12, 21] sperm per 0.01mm2 explant surface from isthmus and ampulla, respectively). The proportion of bound sperm increased from a median of 54% to 62% by seminal fluid treatment. Sperm-oviduct binding could be facilitated by the decelerated sperm motion which was observed in seminal fluid-treated samples or supported by seminal fluid proteins newly attached to the sperm surface. Seminal fluid had no effect on the proportion of sperm with active mitochondria. Extent and pattern of sperm interaction invitro were independent of explant origin from isthmus or ampulla. Sperm were attached to both cilia and microvilli of the main epithelial cell types present in all explants. In contrast to published sperm-binding studies with porcine and bovine oviduct explants where predominantly the anterior head region of sperm was attached to ciliated cells, the tails of some cat sperm were firmly stuck to the oviduct cell surfaces, whereas the heads were wobbling. Whether this response is a preliminary step toward phagocytosis or a precondition to capacitation and fertilization remains to be determined. In conclusion, treatment of epididymal sperm with seminal fluid or particular protein components should be considered in future investigations for its potential to improve the outcome of artificial insemination in felids. © 2015 Elsevier Inc. Source

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