Browsing by Subject "Differenzierung"

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Der Einfluss verschiedener Ölemulsionen und der IL-6-Typ-Zytokine CNTF und LIF auf die Differenzierung von 3T3-L1-Präadipozyten zu Fettzellen
(2009) Stäbler, Antje; Graeve, Lutz
Type 2 diabetes is a disease of civilization spreading all over the world like an epidemic. Among other things it is characterized by increased glucose and triglyceride levels of the blood. Thus the differentiation of preadipocytes into adipocytes that are specialized in storing large fat depots is essential for the removal of excess nutrients from the circulation. This process can be simulated through the differentiation of 3T3-L1 cells by treatment with insulin, IBMX, and dexamethasone. In this study a compensative effect of olive oil as well as soy bean oil on the differentiation of 3T3-L1 cells was found. The differentiation triggered by insulin, IBMX, and dexamethasone was somewhat inhibited by incubating the cells with one of the two oils, whereas both olive and soy bean oil had a certain potential to act as differentiating agents them-selves when insulin, IBMX, and dexamethasone were not added. This points to benefits of certain oils contained in food compared to thiazolidinediones that are used as antidiabetics and lead to weight gain in the long term. Furthermore the inhibitory effect of the proinflammatory cytokine TNFα on the differentiation process could be compensated to some degree by either oil. The transcription factor PPARγ was used to measure the state of differentiation. Caveolin1 is involved in both buildup and degradation of intracellular fat stores and was induced by oil incubation in differentiated as well as in undifferentiated 3T3-L1 cells. Moreover the signal transduction of the IL-6-related cytokine CNTF in 3T3-L1 cells and its influence on the differentiation process of these cells was investigated. In recent years CNTF was spotlighted because of its leptin-like properties that persist even in leptin resistant states. In this study an increasing sensitivity to CNTF during the differentiation of 3T3-L1 cells was shown. Furthermore the positive effects of the cytokine on fatty acid metabolism and adipocyte development were verified. CNTF favored the emergence of many small adipocytes compared to fewer, but larger adi-pocytes under different conditions. Thereby the functionality of the cells is influenced in a positive way and the protection from the development of insulin resistance is increased. The effect of LIF - another IL-6-related cytokine - was not similar to that of CNTF but was more comparable to the effect of the oils.
Geschlechtsspezifische Unterschiede in der Fötalentwicklung beim Schwein
(2007) Häußler, Susanne; Claus, Rolf
Basic mechanisms of sexual differentiation in higher mammals are well established. The development of the testes is controlled by genetic mechanisms and initiated by the Y-chromosome. Further differentiation of the ?Anlagen? is performed by the presence of testicular androgens but requires no specific signal in females (basic femaleness). Speculation exists during the fetal development of pigs, because androgens are also measurable in female fetuses. In addition, the male gonad is able to synthesize remarkably high levels of estrogens. The aim of the present study was to follow up concentrations of steroids in peripheral plasma throughout fetal development, starting with week 6, and in particular to analyze changes in testicular cell populations (spermatogonia, Leydig cells) and to correlate them with testicular androgens, estrogens, 19-nortestosterone and cortisol. The expression of steroid converting enzymes such as 11beta-HSD 2 and aromatase as well as receptors were determined by immunocytochemistry and quantitative PCR. Altogether each of the stages of gestation (weeks 6, 10, 13, and 15 of pregnancy) was represented by 4 sows, so that a total of 158 fetuses were collected. Testicular steroid synthesis (testosterone, estradiol) could be demonstrated as early as week 6, but was independant of gonadotropine. 19-nortestosterone, which is formed during estrogen synthesis, was detected in amniotic fluid using a new established enzymeimmunoassay in this study. Aromatase activity clearly correlated with a wave-like pattern of cell development. Therefore the activity was elevated both during an alternating rise of Leydig cells or spermatogonia mitosis. During the rise of spermatogonia development Leydig cells remained quiescent and during the Leydig cell mitosis spermatogonia remained inactive. An increased aromatase activity was observed both during the rise of spermatogonia and Leydig cell mitosis, and in consequence an elevated concentration of estradiol was found. But during an increased Leydig cell formation aromatase expression and thus estradiol synthesis was taken over by spermatogonia. It is therefore reasonable to resume that estrogens are important mitogenic signals as it was also found earlier in mature boars. The expression of glucocorticoid receptors by spermatogonia could be demonstrated for the first time in fetal pig testes. As also shown for other tissues, its likely role in testes is the differentiation of new cells. This important role also explains the expression of the enzyme 11beta-HSD 2 both by Leydig cells and spermatogonia. This enzyme is a well known fine-tuning mechanism which indicates cortisol and thus the ligand for the glucocorticoid receptor. Its expression in parallel to the rise of estrogens suggests a dependancy on estrogens. Investigating this was, however, not the topic of the present study. The demonstration of androgens both in blood plasma and amniotic fluid in female fetuses seems to contradict the principle of basic femaleness. It was shown however, that concentrations of testosterone in males increase up to 2.01 ng/ml plasma during the main period of sexual differentiation whereas female levels remain at 0.2 ng/ml so that it is simply the concentration which decides where the male differentiation does occur. It can not be ruled out, however, that low concentrations in female fetuses may have an effect on follicular differentiation, as was also demonstrated in mature sows. At the same time androgens could have a mitotic effect caused by insulin-like growth factors (IGF I + II). Thus the present investigation was able to clarify of several new mechanisms and basic data of fetal pig development. Further confirmation of the mechanisms suspected in this study may be served by an aromatase inhibitor.
Potential and prospects of a brand differentiation in the agricultural engineering, using the example of the multi-brand company CNH Industrial
(2023) Münd, Benjamin; Köller, Karlheinz
CNH Industrial unites three agricultural brands, Case IH, Steyr and New Holland. With miscellaneous mergers in the past, these former independent manufacturers of agricultural equipment were combined in one company. A lot of synergies were used and are still being used to maximize the profit of the parent company CNH Industrial and to reduce complexity. Through this harmonization process, the tractor models of the three brands became more and more similar with less distinctive features which leads to a high comparability of the brands Case IH, Steyr and New Holland and its tractor product line up above 55 hp. This results in a strong competition between these brands because in most countries the dealer network is separated for New Holland and Case IH/Steyr and every distribution partner is independent and strives for their own profitability. Due to this, the internal competition prevents external competition with tractors from other manufacturers, which generates cannibalization effects and reduces the profit of the three brands, CNH Industrial and the dealers. Structural changes in the European agriculture led to bigger farms with in total less tractor registrations per year what intensifies additionally the competition for tractor manufacturers. A survey with farmers and contractors from Germany, UK and France showed, that a brand and product differentiation would make sense and would bring a sustainable benefit for all three brands and their parent company CNH Industrial. Because of the history of all three brands and loyal long-term customers, a merger to one CNH Industrial brand is not efficient and expedient. It is important to identify the right customer group for each brand, to know the customers’ requirements and to offer the appropriate products and technical solutions. The network of distribution partners (dealers) is the key factor for an efficient market development. The professionalism of the dealers is mainly determining the success of a brand and its products in the market and the perception of the farmers and contractors. The professionalization of the dealer and collaboration between manufacturing company and dealer is essential. Also, the country of production of the tractors has a significant impact on the customer perception and appreciation. “Made in Germany” is still a quality characteristic and explains partially the high appreciation of Fendt and John Deere as premium tractors for professional farmers and contractors. Steyr as one brand of CNH Industrial AG which only produces tractors has a valid potential to establish to a premium tractor brand in Europe. Due to little negative connotations of customers and a straightforward history the brand has a good base for this development purpose. Bottom line, there are manifold possibilities to achieve a differentiation that is perceived by the customers as such. However, several actions are only feasible mid- or long-term. A product differentiation makes sense to reach a broad base of customers. Certainly, it is undisputed that a product differentiation is connected to high investment. If it is economically viable for the CNH Industrial group remains to be evaluated.