871 resultados para Limb dimension
Resumo:
The role of basolateral membrane Na+/H+ exchange in transepithelial HCO3- absorption (JHCO3) was examined in the isolated, perfused medullary thick ascending limb (MTAL) of the rat. In Na(+)-free solutions, addition of Na+ to the bath resulted in a rapid, amiloride-sensitive increase in intracellular pH. In MTALs perfused and bathed with solutions containing 146 mM Na+ and 25 mM HCO3-, bath addition of amiloride (1 mM) or 5-(N-ethyl-N-isopropyl) amiloride (EIPA, 50 microM) reversibly inhibited JHCO3 by 50%. Evidence that the inhibition of JHCO3 by bath amiloride was the result of inhibition of Na+/H+ exchange included the following: (i) the IC50 for amiloride was 5-10 microM, (ii) EIPA was a 50-fold more potent inhibitor than amiloride, (iii) the inhibition by bath amiloride was Na+ dependent, and (iv) significant inhibition was observed with EIPA as low as 0.1 microM. Fifty micromolar amiloride or 1 microM EIPA inhibited JHCO3 by 35% when added to the bath but had no effect when added to the tubule lumen, indicating that addition of amiloride to the bath did not directly inhibit apical membrane Na+/H+ exchange. In experiments in which apical Na+/H+ exchange was assessed from the initial rate of cell acidification following luminal EIPA addition, bath EIPA secondarily inhibited apical Na+/H+ exchange activity by 46%. These results demonstrate basolateral membrane Na+/H+ exchange enhances transepithelial HCO3- absorption in the MTAL. This effect appears to be the result of cross-talk in which an increase in basolateral membrane Na+/H+ exchange activity secondarily increases apical membrane Na+/H+ exchange activity.
Resumo:
When Dictyostelium discoideum cells are drawn into a fine glass capillary, they rapidly begin the first steps toward the formation of prestalk and prespore zones. Some of the events occur within a minute or two, whereas others follow later. The cells in the front segment are actively motile and those in the hind segment are passive. The volumes of the segments are proportional for different-sized cell masses, and those proportions are the same as those found in normal slugs. When the cells are stained with the vital dye neutral red, the anterior zone becomes darker simultaneously with the formation of the division line. Green fluorescent protein expressed from a stalk-specific promoter is synthesized mostly in the anterior end. Later, this capillary prestalk zone shows a sharp increase in alkaline phosphatase activity, which is known to be characteristic of prestalk cells.
Resumo:
In this paper, we show the conserved regulation of the homeodomain gene Distal-less-3 (Dlx-3) by analyzing the expression of a promoter from the Xenopus ortholog, Xdll-2, in transgenic mice. A 470-bp frog regulatory sequence confers appropriate expression on a lacZ reporter gene in the ectodermal component of structures derived from epithelial-mesenchymal interactions. Remarkably, this includes structures absent in Xenopus, such as the hair follicle and mammary gland, suggesting that conserved regulatory elements can be used to control the formation of structures peculiar to individual species. In addition, expression of Dlx-3 in developing limbs is highest at the most distal portion. This pattern is duplicated by the Xenopus promoter, indicating that this DNA may include sequences responsive to conserved proximodistal patterning signals in the vertebrate limb.
Resumo:
This paper will initially review integral concepts found within Heidegger’s understanding of existence or being - namely the dialectic between authentic and inauthentic living, and by extension, existential guilt, anxiety, and regret. Next, I will discuss a particular dimension of inauthenticity found at the intersection of existential guilt and regret, termed existential dissonance. This term, adapted from Festinger’s theory of cognitive dissonance will serve to illuminate several clinical phenomena. To ground this concept further, I will provide two case examples that further express and clarify this concept.
Resumo:
There is international consensus among scholars that democratic transitions are multicausal processes in which both internal and international variables are involved (Pridham 1991, 1995; Whitehead 1996; Schmitter 1996; Linz and Stepan 1996; Carothers 1999; Morlino and Magen 2008; Grilli di Cortona 2009). This chapter is limited, on the one hand, to the dependent variable consisting solely of the crisis/breakdown/transformation of non-democratic regimes in the Third Wave of democratization, and, on the other hand, to an independent variable identified solely with the international dimension of democratic transition. This factor, which can be termed the Proactive International Dimension (PID), specifically concerns that combination of actions or processes, produced by one or more international actors, that, intentionally or not, cause or contribute to the crisis/breakdown/transformation of a non-democratic regime.
Resumo:
From the Introduction. In the academic year 1991-1992, Utrecht University, on my initiative, started to offer courses in European criminal law. This initiative came at a symbolic moment, just prior to the entry into force of the EU Treaty of Maastricht1 and the outlining of European policy in the areas of Justice and Home Affairs (JHA). The Director of the Legal Department, Paul DEMARET, was aware of the significance of this development and I have been given the opportunity to teach this subject at the College of Europe since 1995. Since then, JHA has evolved into one of the main areas of EU legislation. Now we are again on the threshold of an important historical feat. In June 2003, the European Convention reached agreement concerning a draft Treaty establishing a Constitution for Europe.2 The use of the term “Constitution” for the future EU Treaty is not simply cosmetic. The realisation has dawned that EU integration must be embedded in a treaty document which also regulates the rights and duties of citizens, not just with respect to European citizenship, but also with respect to, for example, Justice. Where JHA is concerned, this result acknowledges that the harmonisation of criminal law and criminal procedure and transnational cooperation cannot preclude the harmonisation of principles of due law and fair trial. Despite the substantial Europeanisation of criminal law, many criminal lawyers are defending the achievements and typicalities of their national criminal law like never before. EU initiatives are assessed from the perspective of the national agenda and national achievements. We are still too far removed from a European criminal law policy that is both European and enjoys national support. The core issue is therefore not how to keep our criminal (procedural) law national and free from European influences, but rather how to ensure democratic decision making, the quality of the constitutional state and the guarantees of criminal law in a national administrative model which has to operate increasingly interactively within a European and international context. In this contribution, the contours of the Europeanisation of criminal law are outlined and analysed. First, attention will be paid to the EC and, second, to the JHA. Following this, an evaluation and a look ahead at the current IGC are indicated.