Dynamics of lipoprotein metabolism in adult growth hormone deficiency

Dyslipidaemia is often associated with adult growth hormone (GH) deficiency. Reduced removal of very-low-density lipoprotein (VLDL) apolipoprotein B-100 (apo B-100) can, in part, explain the "unfavourable" lipid profile of these patients. By modifying VLDL composition and through its action on low-density lipoprotein (LDL) receptors, GH may improve the lipid profile by increasing direct hepatic uptake of VLDL apo B-100, thereby decreasing conversion to LDL. Although GH stimulates VLDL apo B-100 secretion, this is exceeded by its effects in upregulating LDL receptors and modifying VLDL composition. We hypothesize that the improved lipid profile, in particular the decrease in cholesterol-rich VLDL particles, may contribute to a possible antiatherogenic action of GH. GH appears to have an important role in hepatic apo B-100 metabolism. However, we are just at the beginning of understanding the underlying mechanism. Further studies are required to investigate the effect of GH on other lipoprotein classes, in particular VLDL subfractions, intermediate-density lipoprotein, LDL and high-density lipoprotein. The key question, however, remains as to whether GH replacement therapy can reduce cardiovascular mortality. Long-term studies with sufficient numbers of patients are required to answer this question.

A reverse crystal Engineering approach

The enormous impact of crystal engineering in modern solid state chemistry takes advantage from the connection between a typical basic science field and the word engineering. Regrettably, the engineering aspect of organic or metal organic crystalline materials are limited, so far, to descriptive structural features, sometime entangled with topological aspects, but only rarely with true material design. This should include not only the fabrication and structural description at micro- and nano-scopic level of the solids, but also a proper reverse engineering, a fundamental discipline for engineers. Translated into scientific language, the reverse crystal engineering refers to a dedicated and accurate analysis of how the building blocks contribute to generate a given material property. This would enable a more appropriate design of new crystalline material. We propose here the application of reverse crystal engineering to optical properties of organic and metal organic framework structures, applying the distributed atomic polarizability approach that we have extensively investigated in the past few years[1,2].