Scintigraphic Imaging of Endothelium-Dependent Vasodilation in the Forearm - A Preliminary Report

Background The diagnosis of endothelial dysfunction has been gaining, clinical importance, but although endothelial function testing is available in the research setting, no technique yet exists that is simple, safe, reproducible and easily performed as a clinical screening method. The aim of this study was to design a new, scintigraphic method of imaging the flow-mediated dilation in the forearm, which represents the functional characteristic of endothelial dysfunction. Methods and Results The study group comprised 118 subjects in whom left forearm ischemia was induced by inflating a sphygmomanometer cuff to supra systolic pressure for 4.5min. Later, dynamic acquisition (2s frame/min) was initiated after the injection of technetium-99m methoxy-isobutyl isonitril into the dorsal pedal veins. Equivalent regions of interest were drawn on both arms to detect total activity counts during 1 min and the perfusion ratios (left arm/right arm) were calculated. The left arm counts (22,203.3 +/- 12.372.7) were significantly higher than the right arm counts (9,980.9 +/- 5,931.9) (p < 0.001). A significant decrease in perfusion ratios was noted in the hypertension and hypercholesterolemia groups. An increase in the number of risk factors caused an insignificant decrease in perfusion ratio (p=0.346). Conclusion Non-invasive evaluation of endothelium-dependent vasodilation by semiquantitative scintigraphic method using radioactive perfusion tracer provided promising results.Wo

Distinct organ-specific up- and down-regulation of IGF-I and IGF-II mRNA in various organs of a GH-overexpressing transgenic Nile tilapia

Several lines of GH-overexpressing fish have been produced and characterized concerning organ integrity, growth, fertility and health but few and contradictory data are available on IGF-I that mediates most effects of GH. Furthermore, nothing is known on IGF-II. Thus, the expression of both IGFs in liver and various extrahepatic sites of adult transgenic (GH-overexpressing) tilapia and age-matched wild-type fish was determined by real-time PCR. Both IGF-I and IGF-II mRNA were found in all organs investigated and were increased in gills, kidney, intestine, heart, testes, skeletal muscle and brain of the transgenics (IGF-I: 1.4-4-fold; IGF-II: 1.7-4.2-fold). Except for liver, brain and testis the increase in IGF-I mRNA was higher than that in IGF-II mRNA. In pituitary, no significant change in IGF-I or IGF-II mRNA was detected. In spleen, however, IGF-I and IGF-II mRNA were both decreased in the transgenics, IGF-I mRNA even by the 19-fold. In agreement, in situ hybridisation revealed a largely reduced number of IGF-I mRNA-containing leukocytes and macrophages when compared to wild-type. These observations may contribute to better understanding the reported impaired health of GH-transgenic fish. Growth enhancement of the transgenics may be due to the increased expression of both IGF-I and IGF-II in extrahepatic sites. It is also reasonable that the markedly enhanced expression of liver IGF-II mRNA that may mimick an early developmental stage is a further reason for increased growth

Protein/Emulsifier Interactions

An important consequence of protein-lipid interaction is the effect on stability of the protein in solution as well as on its behavior at interfaces. Here we will discuss key aspects of protein aggregation and unfolding as well as the effects of protein structure (random coil proteins versus globular) that are relevant for our understanding protein-lipid interaction. The main types of emulsifiers are the (1) aqueous soluble, surfactant type and (2) lipids with low aqueous solubility. The monomer concentration as defined by cmc is an important parameter for the soluble lipids. For emulsifiers with low aqueous solubility the emulsifier self-assembly structure and its properties control the interaction with proteins. We will therefore summarize the main features of lipid self-assembly. It also allows us to define different plausible scenarios and principles and models for factors that control the interactions in real food (and Pharmaceutical) systems. For the food applications the fate of the lipid during digestion is important and therefore we will discuss some aspects of enzyme-catalyzed lipolysis in terms of the structural evolution. New products and concepts of using protein/emulsifier interactions will be exemplified by illustrating how food nanotechnology possibly can be used for the delivery of functionality